Mechanisms for efficient access and transmission in nr

ABSTRACT

Methods, systems, and apparatuses are described herein for beamforming based initial access, beam management, and beam based mobility designs for NR systems. Issues are identified and addressed related to, for example, initial access, control channel design, eMBB and URLLC mixing, and beam training.

CROSS-REFERENCE TO RELATED APPLICATIONS

This applications claims the benefit of U.S. Provisional Application No.62/443,497 filed Jan. 6, 2017 and U.S. Provisional Patent ApplicationNo. 62/453,855 filed Feb. 2, 2017, the disclosures of which are herebyincorporated by reference.

BACKGROUND

3GPP TR 38.913 “Study on Scenarios and Requirements for Next GenerationAccess Technologies” (Release 14, V0.2.0) defines scenarios andrequirements for New Radio (NR) technologies. Key Performance Indicators(KPIs) for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low LatencyCommunication (URLLC), and massive Machine-Type Communication (mMTC)devices are summarized in Table 1, by way of example:

TABLE 1 KPIs Device KPI Description Requirement URLLC Control PlaneControl plane latency refers to the time to move from a 10 ms Latencybattery efficient state (e.g., IDLE) to start of continuous datatransfer (e.g., ACTIVE). Data Plane For URLLC the target for user planelatency for UL and DL. 0.5 ms Latency Furthermore, if possible, thelatency should also be low enough to support the use of the nextgeneration access technologies as a wireless transport technology thatcan be used within the next generation access architecture. ReliabilityReliability can be evaluated by the success probability of 1-10⁻⁵transmitting X bytes within 1 ms, which is the time it takes within 1ms. to deliver a small data packet from the radio protocol layer 2/3 SDUingress point to the radio protocol layer 2/3 SDU egress point of theradio interface, at a certain channel quality (e.g., coverage-edge).mMTC Coverage “Maximum coupling loss” (MCL) in uplink and downlink 164dB between device and Base Station site (antenna connector(s)) for adata rate of [X bps], where the data rate is observed at theegress/ingress point of the radio protocol stack in uplink and downlink.UE Battery Life User Equipment (UE) battery life can be evaluated by the15 years battery life of the UE without recharge. For mMTC, UE batterylife in extreme coverage shall be based on the activity of mobileoriginated data transfer consisting of [200 bytes] Uplink (UL) per dayfollowed by [20 bytes] Downlink (DL) from Maximum Coupling Loss (MCL) of[tbd] dB, assuming a stored energy capacity of [5 Wh]. ConnectionConnection density refers to total number of devices 10⁶ Densityfulfilling specific Quality of Service (QoS) per unit area devices/km²(per km²). QoS definition should take into account the amount of data oraccess request generated within a time t_gen that can be sent orreceived within a given time, t_sendrx, with x % probability.

SUMMARY

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This summary is not intended to limit the scope of theclaimed subject matter. The foregoing needs are met, to a great extent,by the present application directed methods, systems, and apparatusesdescribed herein for beamforming based initial access, beam management,and beam based mobility designs for NR systems. Issues are identifiedand addressed related to, for example, initial access, mini-slot andcontrol channel design, enhanced Mobile Broadband (eMBB), andUltra-Reliable Low Latency Communication (URLLC) mixing, and beamtraining and recovery.

With respect to initial access issues, in accordance with variousexample embodiments, synchronization signals (SS) are multiplexed andtiming-index methods for secondary synchronization signals (SSS) aredescribed herein. In one embodiment, an SSS can use message-basedaspects, instead of using a training sequence, and a CRC can be maskedwith a timing-index. In another embodiment, an SS can have a differentsetup at the connected-mode (e.g., on-demand or configured by DCI/SIB orRRC). Discovery signals for NR and a paging channel associated with SSare also described herein.

In one aspect of the application related to initial access, a SS burstdesign method for UE is described that does not need knowledge of the SSblock distribution. In an example, an apparatus, for instance a UE, canmonitor a synchronization signal block burst that comprises a pluralityof synchronization signal blocks. Based on the monitoring, the apparatusmay select a synchronization signal block from the synchronizationsignal block burst. The apparatus may obtain a timing index from theselected synchronization signal block. Based on the timing index, theapparatus may determine initial access information, and communicate withthe network in accordance with the initial access information. Thesynchronization signal block may include at least one primarysynchronization signal and secondary synchronization signal, and thetiming index may be embedded in the secondary synchronization signal. Inanother example, the timing index is embedded in a reference signal ofthe synchronization signal block. For example, the apparatus maycommunicate with a cell of the network having an identity, and receivethe reference signal that is a function of the identity of the cell andtiming information associated with the synchronization signal block. Inanother example, the synchronization signal block has a position withinthe SS block burst, and the timing index is based on the position withinthe SS block burst. Further, the apparatus may receive a paging occasionwith a paging indication associated with the synchronization signalblock.

In another embodiment, support of multi-beam transmissions in a beamsweeping SS block reduces the beam sweeping time for initial access. Ifmulti-beams are used in a sweeping block, the explicit beam ID signalingmay be required. In an embodiment of this aspect, a method for carryingsystem information via NR-PBCH and other channels is described. Systeminformation is carried by a broadcast channel. The broadcast channelincludes resource allocation and demodulation reference signal (DMRS)design. In another step, system information may be carried by aNR-PDSCH. Further, system information may be carried by a NR-PDCCH. Inanother embodiment of this aspect, NR-PBCH timing indication methods areemployed. In another embodiment of this aspect, PRACH power boosting andbeam reselection methods, when RAR is not received, are employed.

With respect to control channel design issues, in accordance withvarious embodiments, mini-slot types, indications of mini-slotconfigurations, and example mini-slot structures are described herein.With respect to eMBB and URLLC mixing, in various example embodiments,issues related to the URLLC transmission being super-positioned on topof the eMBB transmission are addressed. In some cases, the URLLCtransmission may alone be transmitted, and no eMBB transmission mayoccur on those resources. In various examples, the eMBB UE may havetimely knowledge, delayed knowledge, or no knowledge of a pre-emptiveURLLC transmission.

Yet even another aspect of the application is directed to controlsignaling and HARQ mechanisms. In one embodiment, downlink (DL) controlsignaling is employed for resource allocation for group common PDCCH inNR. In another embodiment, uplink (UL) control signaling is employed forresource allocation of short and long PUCCH. In yet another embodiment,a HARQ mechanism is employed for richer A/N transmission and UEcapabilities. In a further embodiment, URLLC transmissions are employedfor compact PDCCH for URLLC.

With respect to beam training, new beamforming training methods aredisclosed herein. For example, the latency for the beamforming trainingprocessing time may be reduced in accordance with various embodiments.In one example, the beamforming training only requires performing asingle stage/phase (beam sweeping) instead of two phases (sector levelsweeping and beam refinement phase) in the beam training process. Anexample beamforming training sequence design is also described herein,which may be used not only to mitigate neighbor training beams from thesame or different TRPs, but also to identify the transmit beamformingvector associated with a predefined beamforming codebook. In accordancewith another example embodiment, a mechanism is described to estimatethe direction of departure (DoD) and the direction of arrival (DoA) fromthe received directional training beams, where the estimated DoD can beused as the feedback instead of using finer beam sweeping in the beamrefinement stage.

Yet another aspect of the application is directed to beam management,wherein a beam recovery process minimizes the radio link failuredeclaration for multi-beam based NR networks. In an example, a firstlevel recovers current serving beams. In another example, currentserving beams are replaced with alternative beams. Mechanisms areemployed to measure and evaluate the serving beams and other alternativebeams. Various events and threshold values may trigger the beam recoveryprocess. Transition rules between different phases of the beam and linkrecovery process are described. In another embodiment of this aspect, abeam diversity transmission scheme for PDCCH is envisaged. Here, the UEmay monitor multiple beams including active and non-active beams. Theactive beams may be selected by the gNB from a subset of monitoredbeams. In an example, the beam candidate set is updated and new beamsweeping and beam refining is initiated when most of the monitored beamsare downgraded. A UE-specific search space design and blinding decodingmechanisms are also described.

Yet another aspect is directed to preemption. In an example, anapparatus sends a first transmission and a second transmission, and theapparatus may assign resources of the first transmission to the secondtransmission, so as to preempt the first transmission with the secondtransmission. The apparatus may send control information so as toexplicitly indicate that the second transmission should preempt thefirst transmission, and the control information may further indicate atleast one resource for preemption. Alternatively, the apparatus maytransmit a reference signal that indicates preemption information, so asto implicitly indicate that the second transmission should pre-empt thefirst transmission. The first transmission may be overwritten by thesecond transmission at select resource locations of the firsttransmission. In some cases, the first transmission skips resourcesselected for preemption by the second transmission. Further, theapparatus may transmit a control signal that indicates that the firsttransmission should be preempted by the second transmission. The controlsignal can be transmitted in a mini-slot that also carries the secondtransmission. Alternatively, the control signal may be transmitted insubsequent slot to the mini-slot that carries the second transmission.

This Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter. Furthermore,the claimed subject matter is not limited to limitations that solve anyor all disadvantages noted in any part of this disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an example of cell coverage with sector beams andmultiple high gain narrow beams.

FIG. 2 depicts example multiplexing methods for synchronization signals(SS): (A) frequency division multiplexing (FDM), (B) time divisionmultiplexing (TDM), and (C) Hybrid.

FIG. 3 depicts an example of repeated or multiple primarysynchronization signals (PSS) and secondary synchronization signals(SSS) symbols in an SS block.

FIG. 4 shows configured SS transmission in the connected-mode and thebroadcast SS in the idle-mode in accordance with an example.

FIG. 5 shows a user equipment (UE) method for an on-demand SStransmission in connected-mode in accordance with an example embodiment.

FIG. 6 shows an example of a periodic discovery signal (DS) in new radio(NR) (NR-DS).

FIG. 7 shows an example of a repeated physical broadcast channel (PBCH)and demodulation reference signal (DMRS) design in an SS block.

FIG. 8 depicts a paging occasion (PO) share with SS burst for idle-modeand connected-mode in accordance with an example.

FIG. 9 illustrates an example radio link failure in LTE in accordancewith an aspect of the application.

FIG. 10 illustrates an example consecutive burst block design in a SSburst according to an aspect of the application.

FIG. 11 illustrates an example non-consecutive burst block design in aSS burst according to an aspect of the application.

FIG. 12 illustrates an example broadcast channel carrying remainingminimum system information (RMSI) and sharing the same beamconfiguration with a defined SS burst in an initial access according toan aspect of the application.

FIG. 13 illustrates an example broadcast channel carrying RMSI userefinement beams based on a defined SS burst in the initial accessaccording to an aspect of the application.

FIG. 14 illustrates an example physical downlink control channel (PDCCH)for NR (NR-PDCCH) carrying SI use refinement beams or a similar beambased on a defined SS burst in the initial access according to an aspectof the application.

FIG. 15 illustrates an example search space for NR-PDCCH withassociation of beam ID and time frequency resources according to anaspect of the application.

FIG. 16 illustrates an example UE monitoring more than one beam in theinitial access for physical random access channel (PRACH) retransmissionaccording to an aspect of the application.

FIGS. 17A and 17B depict examples of mini-slots in accordance with anexample embodiment.

FIG. 18 shows a dynamic Indication of mini-slot configuration inaccordance with an example embodiment.

FIG. 19 depicts examples of a mini-slot structure in accordance with anexample embodiment.

FIG. 20 depicts examples of preemptive Ultra-Reliable Low LatencyCommunication (URLLC) resource configuration over enhanced MobileBroadband (eMBB) transmissions: (A) distributed frequency resources, (B)contiguous frequency resources, and (C) frequency hopped resources.

FIG. 21 depicts an example numerology for URLLC transmissions that is(A) the same as eMBB and (B) different from eMBB.

FIG. 22 is a flow diagram that shows an example of a eMBB UE's method todecode its payload in the presence of pre-emptive URLLC transmissionwith a different modulation/numerology, according to an embodiment.

FIG. 23 is a flow diagram that shows an example of a eMBB UE's method todecode its payload in the presence of pre-emptive URLLC transmissionusing distinct reference signals for URLLC transmission, according to anembodiment.

FIG. 24 shows examples of allocations of Physical Preemption Indicationchannel (PPIC) resources in different scenarios: (A) localized frequencyresources, (B) distributed frequency resources, (C) multiple PPICs in asingle eMBB DL grant, and (D) multi-symbol PPIC.

FIG. 25 depicts an example control region in a mini-slot to indicateURLLC transmission for (A) distributed resources and (B) localizedresources.

FIG. 26 depicts different mini-slot down link control information (DCI)formats for eMBB and URLL UEs to indicate the URLLC resources, inaccordance with an example embodiment.

FIG. 27 shows a common mDCI format to indicate the location of the URLLCtransmission in accordance with an example embodiment.

FIG. 28 shows a common control region indicating the preemptive URLLCtransmission in accordance with an example embodiment.

FIG. 29 shows an example URLLC indication in subsequent control regionsin accordance with an example embodiment.

FIG. 30 shows an example of code bock (CB) mapping over multiple symbolsof a resource grid.

FIG. 31 depicts examples of a contiguous CB transmission;

FIG. 32 shows an example of a prescheduled URLLC transmission that isindicated through DCI shared with an eMBB, in accordance with an exampleembodiment.

FIG. 33 shows an example of a URLLC scheduled via mini-slot according toan example embodiment.

FIG. 34 illustrates an example of signaling the group common PDCCHthrough a SS burst according to an aspect of the application.

FIG. 35 illustrates an example of signaling the group common PDCCH viaDCI according to an aspect of the application.

FIG. 36 illustrates an example short PUCCH resources allocation in a DLcentric subframe according to an aspect of the application.

FIG. 37 illustrates an example short PUCCH resources allocation in a ULcentric subframe according to an aspect of the application.

FIG. 38 illustrates example PUCCH bands with resources reserved for longPUCCH according to an aspect of the application.

FIG. 39 illustrates an example PUCCH band selection for resourceallocation for UEs according to an aspect of the application.

FIG. 40 illustrates an example (ACK/NACK) (A/N) bit allocation per groupof CBs according to an aspect of the application.

FIG. 41 illustrates an example of URLLC puncturing eMBB transmissionaccording to an aspect of the application.

FIG. 42 illustrates an example hybrid automatic repeat request (HARQ)retransmission occurring on a transmission time interval (TTI) of adifferent numerology according to an aspect of the application.

FIG. 43 depicts an example of beam sweeping burst and blocks inaccordance with an example embodiment.

FIG. 44 illustrates beam recovery and radio link failure (RLF) at highfrequency for new radio (HF-NR) according to an aspect of theapplication.

FIG. 45 illustrates an example procedure for updating the beammonitoring and candidate sets according to an aspect of the application.

FIG. 46 illustrates an example mapping between time-frequency (TF)resources and UE and beam ID according to an aspect of the application.

FIG. 47A illustrates one embodiment of an example communications systemin which the methods and apparatuses described and claimed herein may beembodied.

FIG. 47B is a block diagram of an example apparatus or device configuredfor wireless communications in accordance with the embodimentsillustrated herein.

FIG. 47C is a system diagram of an example radio access network (RAN)and core network in accordance with an example embodiment.

FIG. 47D is another system diagram of a RAN and core network accordingto another embodiment.

FIG. 47E is another system diagram of a RAN and core network accordingto another embodiment.

FIG. 47F is a block diagram of an exemplary computing system 90 in whichone or more apparatuses of the communications networks illustrated inFIGS. 47A and 47C-E may be embodied.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

A detailed description of the illustrative embodiment will be discussedin reference to various figures, embodiments and aspects herein.Although this description provides detailed examples of possibleimplementations, it should be understood that the details are intendedto be examples and thus do not limit the scope of the application.

Reference in this specification to “one embodiment,” “an embodiment,”“one or more embodiments,” “an aspect” or the like means that aparticular feature, structure, or characteristic described in connectionwith the embodiment is included in at least one embodiment of thedisclosure. Moreover, the term “embodiment” in various places in thespecification is not necessarily referring to the same embodiment. Thatis, various features are described which may be exhibited by someembodiments and not by the other.

Currently 3GPP standardization's efforts are underway to design theframework for beamformed access. The characteristics of the wirelesschannel at higher frequencies are significantly different from the sub-6GHz channel that LTE is currently deployed on. It is recognized hereinthat a key challenge of designing the new Radio Access Technology (RAT)for higher frequencies will be overcoming the larger path-loss at higherfrequency bands. In addition to this larger path-loss, the higherfrequencies are subject to an unfavorable scattering environment due toblockage caused by poor diffraction. Therefore, MIMO/beamforming may beessential in guaranteeing sufficient signal level at the receiver end.

Relying solely on MIMO digital precoding used by digital BF tocompensate for the additional path-loss in higher frequencies might notbe enough to provide similar coverage as below 6 GHz. Thus, the use ofanalog beamforming for achieving additional gain can be an alternativein conjunction with digital beamforming. A sufficiently narrow beam maybe formed with lots of antenna elements, which is likely to be quitedifferent from the one assumed for the LTE evaluations. For largebeamforming gain, the beam-width correspondingly tends to be reduced,and hence the beam with the large directional antenna gain cannot coverthe whole horizontal sector area specifically in a 3-sectorconfiguration. The limiting factors of the number of concurrent highgain beams include, for example, the cost and complexity of thetransceiver architecture.

From the observations above, multiple transmissions in the time domainwith narrow coverage beams steered to cover different serving areasmight be necessary, in some cases. Inherently, the analog beam of asubarray can be steered toward a single direction at the time resolutionof a OFDM symbol, or at any appropriate time interval unit defined forthe purpose of beam steering across different serving areas within thecell, and hence the number of subarrays may determine the number of beamdirections and the corresponding coverage on each OFDM symbol or timeinterval unit defined for the purpose of beams steering. In some cases,the provision of multiple narrow coverage beams for this purpose hasbeen called “beam sweeping.” For analog and hybrid beamforming, in somecases, the beam sweeping may be essential to provide the basic coveragein NR. This concept is illustrated in FIG. 1, where the coverage of asector level cell 200 is achieved with sector beams 202 a and 202 b andmultiple high gain narrow beams 204. Also, for analog and hybridbeamforming with massive MIMO, multiple transmissions in the time domainwith narrow coverage beams steered to cover different serving areasmight be essential to cover the whole coverage areas within a servingcell in NR, in some cases.

One concept closely related to beam sweeping is the concept of beampairing, which is used to select the best beam pair between a UE and itsserving cell, which can be used for control signaling or datatransmission. For the downlink transmission, a beam pair may consist ofa user equipment (UE) receive (RX) beam and a new radio node (NR-Node)transmit (TX) beam. With respect to uplink transmission, a beam pair mayconsist of an UE TX beam and an NR-Node RX beam.

Another related concept is the concept of beam training, which is usedfor beam refinement. For example, as illustrated in FIG. 1, a coarsersector beamforming may be applied during the beam sweeping and sectorbeam pairing procedure. A beam training may then follow, where forexample the antenna weights vector are refined, followed by the pairingof high gain narrow beams between the UE and NR-Node 201.

Issues regarding initial access are identified and addressed herein. InNR, the initial access channel, such as synchronization signal (SS) forexample, may have different setup for a UE that is in the idle-mode orconnect-mode. For a beamforming system, different SS signal setupinvolves multiple design parameters, such as number of training beams,number of SS symbols, and SS burst periodicity, etc. In addition, it isrecognized herein that SS for the discovery reference signal (DRS) in NRshould be addressed because there is no training beam structure andsupport for different numerologies in the current long term evolution(LTE) systems.

Issues regarding control channel design are identified and addressedherein. To support different numerologies in a subframe structure, themini-slot design may be essential. How to optimize the mini-slot designfor efficient resource usage is an example problem that is addressedherein.

Issues regarding enhanced mobile broadband (eMMB) and ultra-reliable lowlatency communication mixing are identified and addressed herein. Inorder to meet the latency requirements for URLLC, URLLC may be scheduledover an ongoing eMBB transmission. Disclosed herein are techniques toprovide resources to URLLC while impacting the eMBB performanceminimally—this may impact design of eMBB code blocks, eMBB, and URLLCresources scheduling, and eMBB hybrid automatic repeat request (HARQ)processes. In some cases, the URLLC transmission can be transparent tothe eMBB user; if not, it is recognized herein that techniques may berequired to indicate the URLLC transmission to the eMBB UE.

Issues regarding beam training are identified and addressed herein. Inthe 5G system, it is recognized herein that a challenge of designing thenew radio access technology for higher frequencies will be overcomingthe larger path-loss at higher frequency bands. In addition to thislarger path-loss, the higher frequencies are subject to unfavorablescattering environment due to blockage caused by poor diffraction.Hence, it is recognized herein that beamforming may be essential inguaranteeing sufficient signal level at the receiver end. The beamtraining procedure can be essential to a beamforming system. In general,the beam training procedure may involve two stages. The first stage inthe beam training is using coarse beam sweeping, it also called asSector Level Sweep (SLS). In the SLS stage, coarse beams are applied fora receiver to identify which sweep sector is the strongest sector(coarse beam). Once a strongest coarse beam has been identified by thereceiver, then it can enter the beam refinement phase (BRP). In the beamrefinement phase, the receiver can refine the beamforming quality byiteratively receiving the refined beams from the transmitter and thoserefined beams can be derived from the identified coarse beam at the SLSphase. However, this method may require several trails and beamsearching between the transmitter and receiver during the beamrefinement phase. It may potentially lead to increasing the beamtraining latency in the beam training procedure. Therefore, it isrecognized herein that a new mechanism may be desired to improve thebeam training latency and enhance the beam training quality.

As initial matter, it is noted that, unless otherwise specified, themechanisms described herein may be conducted at an NR-node, Transmissionand Reception Point (TRP), or Remote Radio Head (RRH). ThereforeNR-node, TRP, and RRH can be used interchangeably herein, withoutlimitation, though an NR-node is used most often for simplicity.Further, unless otherwise specified, the time intervals that containsdownlink (DL) and/or uplink (UL) transmissions are flexible fordifferent numerologies and radio access network (RAN) slices, and may bestatically or semi-statically configured. Such time interval structuresmay be used for a slot or a mini-slot within a subframe. The mechanismsproposed for this time interval structure may be applicable to slotand/or mini-slot, though the descriptions and/or illustrations use slotor mini-slot for exemplary purposes.

Turning now to embodiments related to initial access, NR initial accessdesign is now addressed. The initial access synchronization signalincludes PSS and SSS (hereafter we refer to primary synchronizationsignals (PSS) and secondary synchronization (SSS) as synchronizationsignals (SS) for simplicity) with or without a physical broadcastchannel. The PSS may contain a sequence for a UE to first conduct timeand frequency synchronization. The PSS may also contain a time boundary,such as a frame, subframe or slot boundary. The SSS may contain theidentification of a cell for a UE to select or reselect. In addition, insome cases, the combination of the PSS and the SSS may indicate an OFDMsymbol boundary in time. In the following section, we discuss exampledetails of an SS design.

The PSS and SSS can various multiplexing methods, such as, for example,frequency division multiplexing (FDM), time division multiplexing (TDM)or hybrid FDM/TDM. If PSS and SSS are multiplexed in the same orthogonalfrequency division multiplexing (OFDM) symbol, then the PSS and SSS aremultiplexed using FDM. If PSS and SSS are multiplexed in different OFDMsymbols, then PSS and SSS are multiplexed using TDM. If PSS and SSS aremultiplexed in both time and frequency domain (i.e. mixed into differentOFDM symbols), then PSS and SSS can be multiplexed using hybrid FDM/TDM.These multiplexing SS methods are depicted in FIG. 2. In a beamformingsystem, SS symbols are transmitted with different beams and each SS maybe associated with a single beam or multiple beams in a beam sweepingblock. Each beam sweeping SS block contains a single OFDM or multipleOFDM symbols, and multiple SS blocks form a SS block beam sweepingburst. The periodicity of the SS block burst might have differentperiodicities. Those supported periodicities can be varied withfrequency bands or different numerologies. To enhance the detectionprobability of an SS in one SS block, the PSS and SSS may be repeated oruse multiple PSS and SSS, and span into multiple OFDM symbols. Anexample of the repetition of PSS and SSS in an example SS block 300 isdepicted in FIG. 3. The repetition of PSS and SSS can improve thefrequency offset estimation at the initial access stage. In addition,the SSS sequence can carry a timing index to explicitly signal thetiming difference of the symbol to subframe boundary.

For example, if there are M SS blocks in a SS burst 302 or SS burstblock burst 302 and each SS block 300 is composed of N OFDM symbols,when the SSS sequence is detected and the timing index from the SSSsequence is obtained, then it can calculate the symbol to the subframeboundary. The timing index can be signaled in various ways. In oneexample, the timing index represents the number of symbols to thesubframe boundary or the symbol index within a subframe. In anotherexample, the timing index represents the SS block index within a SSburst. In some cases, the SS block index represents a position of therespective SS block within the first (e.g., first, second, third, etc.).Thus, the SS block can have a position within the SS burst, and thetiming index can be based on the position within the burst. In the firstexample, once the timing index is obtained from the SSS sequence, thenthe timing index can be directly used for the indication of the symbolto subframe boundary. In the second example, it may have to convert theSS block index (timing) to the symbol timing index. Consider an examplecase where the first OFDM symbol in a SS block is the SSS signal(symbol). If a UE detects that the value m as the timing index carriedin the SSS sequence, then the symbol to subframe index can be calculatedas m×N, 0≤m≤M−1 (where N is the number of OFDM symbols within a SS block300).

Thus, as described with reference to FIG. 3, an apparatus, for instancea UE, can monitor a synchronization signal block burst that comprises aplurality of synchronization signal blocks. Based on the monitoring, theapparatus may select a synchronization signal block from thesynchronization signal block burst. The apparatus may obtain a timingindex from the selected synchronization signal block. Based on thetiming index, the apparatus may determine initial access information,and may communicate with the network in accordance with the initialaccess information. The synchronization signal block may include atleast one primary synchronization signal and secondary synchronizationsignal, and the timing index may be embedded in the secondarysynchronization signal. In another example, the timing index is embeddedin a reference signal of the synchronization signal block. For example,the apparatus may communicate with a cell of the network having anidentity, and receive the reference signal that is a function of theidentity of the cell and timing information associated with thesynchronization signal block. In another example, the synchronizationsignal block has a position within the burst, and the timing index isbased on the position within the burst.

In some cases, the SSS might use the coding method to construct SSSinstead of using SSS sequences. The message based SSS can be constructedby the following, presented by way of example and without limitation:

-   -   The payload of SSS can be expressed as d_(sss)={d₀, d₁, . . .        d_(N)} where N is the SSS payload length and d_(i) is the SSS        data bit.    -   The coded SSS can be expressed as C_(sss)={c₀, c₁, . . . c_(M)},        the coding method can choose reed-muller or polar coding, where        M is the channel coder output length.    -   The coded SSS bits C_(sss) may perform rate matching:        R_(sss)={r₀, r₁, . . . r_(O)} where O is the rate-matching        output bits.    -   The SSS rate matching bits R_(sss) then undergo bit interleaver        to form I_(sss)={i₀, i₁, . . . i_(O)} and attach with Q bits CRC        to from the transmit bit D_(sss)={i₀, i₁, . . . i_(O), e₀, e₁, .        . . , e_(Q−1)}    -   The D_(sss) and demodulation reference signal are mapped to one        or several OFDM symbols.

In an example, the attached Q bits CRC can be masked with a timing indexbits such it can implicitly signal the timing index to subframe boundaryin a SS block. If the Q bits CRC for each SSS message is masked with atiming index sequence, then this masked timing index bits can be usedfor implicit indication of symbol to subframe index. This masking timingindex may have various designs. In accordance with one example, thetiming-index represents the number of symbols to the subframe boundary.Hence, the timing index can be directly used for the indication of thesymbol to subframe boundary. In accordance with another example, thetiming index indicates which SS block in a SS burst. Then, in thisexample, the UE may have to convert the block timing index to the symboltiming index, and UE is required to know the SSS OFDM symbol location ina SS block.

Turning now to example when a UE is in the connected-mode, withreference to FIG. 4, the NR-node may configure different types of SSs ascompared to the SS in the idle-mode. There are several differencesbetween idle-mode and connected-mode SS. For example, when a UE is inthe connected-mode, an eNB might allocate some physical resource blocks(PRBs), and those allocated PRBs might be farther away than the SSbroadcast for the idle-mode. Hence, UE can perform measurement withoutmonitoring at least two far away distinct PRBs at the same time. By wayof another example, in a beamforming network, the number of configuredtraining beams, SS burst periodicity and number of PSS, SSS symbols in aSS block might be different than the training beams broadcast for UEmonitoring in the idle-mode. By way of yet another example, the SS inthe connected-mode can be transmitted on-demand (for example, uponreceiving synchronization request from a UE). This on-demand SS can beconfigured in accordance with the example depicted in FIG. 5.

Referring to FIG. 5, in accordance with the example, a given UEdetermines whether it is in connected-mode, at 502. If the UE is in theconnected-mode, the process can proceed to 504, where the UE determineswhether the SS for the connected-mode has been preconfigured, forinstance via radio resource control (RRC) signaling or a systeminformation block (SIB). If the SS has been preconfigured, the processcan proceed to 505, where the UE monitors the preconfigured SS at theallocated location. If the SS has not been preconfigured, the processcan proceed to 506, where the UE can send a request, using a randomaccess channel or a NR physical uplink control channel (NR-PUCCH) forexample, to an eNB or the like for an SS broadcast. At 508, once the eNBreceives the UE request, the eNB may grant or decline the request. At510, if the eNB grants the request for the SS transmission in theconnected-mode, the UE may monitor the SS. The transmission of SS may begranted via a new radio physical downlink control channel (NR-PDCCH).The content of the configured SS information may include variousinformation such as allocated PRBs, number of training beams, SS burstconfiguration, SS burst periodicity, etc. The SS parameters can beeither configured via semi-static or dynamic methods. If the request isnot granted at 510, the UE can receive, at 512, a message indicatingthat there was a failure to satisfy the request. If it is determined (at502) that the UE is not in the connected-mode, process can proceed to503, where the UE falls back mechanism in other modes that are notconnected-mode.

In some cases, a UE can monitor bursts, for instance both the SS in theconnected-mode and the broadcast SS in the idle-mode. The monitoring maydepend on the UE capabilities or UE categories. In some cases, the UEcan monitor the connected-mode SS only when the UE is in the connectedmode. An example of monitoring SS in connected-mode and idle-mode isdepicted in FIG. 4, wherein there are different time intervals betweenSS bursts. As shown there is a different time interval in the idle mode(shown on top) as compared to the connected mode (shown in bottom).

Turning now to a discovery signal (DS), in accordance with an exampleembodiment, an NR Discovery signal (NR-DS) may be used in the NR systemto enhance energy-efficient cell discovery of small cell, D2D andoperation in unlicensed band (LAA) and other occasions. An example NR-DSoccasion for a cell consists of a period with a duration of K1 to K2consecutive subframes for licensed band operation (e.g., frame structuretypes 1 and 2); and K_(n1) OFDM symbols within one non-empty subframefor frame structure type 3. The UE in the downlink subframes may assumethe presence of a discovery signal. The discovery signal may consist ofcell-specific reference signals (denoted as X-RS here) on one or moreantenna ports sweeping through different beams (single-beam or multiplebeams). The antenna ports can be pre-defined or defined by a parameterconfigured by higher layer signaling. The number of beams to sweepthrough can be a system parameter configured by higher layers.Cell-specific reference signals can include a reference signal for phasetracking, a reference signal for time/frequency tracking, a referencesignal for radio link monitoring, a reference signal for RRMmeasurement, or the like. Cell-specific reference signals may alsoinclude Synchronization signals (SS) sweeping through different beams(e.g., single-beam or multiple beams). In some cases, the SS in thediscovery signal transmitted in each beam direction may consist of PSS,SSS and TSS. For each beam direction, PSS, SSS, and TSS may be mapped tothe same OFDM symbols (but different subcarriers), or mapped todifferent OFDM symbols.

Cell-specific reference signals may also include non-zero-power channelstate information (CSI)-reference signals (CSI-RS) transmitted on one ormore antenna ports sweeping through different beams (single-beam ormultiple beams) in zero or more subframes in the period of a discoverysignal burst. In some cases, up to K_(CSI) reserved CSI-RS resources aspart of the discovery signal is configured by higher layer signaling.The CSI-RS may carry information such as the TP index implicitly. Theantenna ports can be either pre-defined or be a parameter configured byhigher layer signaling. The X-RS, SS and CSI-RS (if present) in thediscovery signal will sweep through the same beam directions. The X-RS,SS and CSI-RS (if present) transmitted on the same beam direction can beplaced/mapped to the same OFDM symbol or different (adjacent) OFDMsymbols.

For licensed band operation, the NR-DS may be transmitted with a higherlayer configured periodicity. Alternatively, the NR-DS can betransmitted by the gNB on-demand (for example, upon receivingsynchronization request from a UE). For unlicensed band operation, in anexample, the UE may assume that a NR-DS is transmitted in any subframewithin the discovery signals measurement timing configuration. Anexample of periodic NR-DS is shown in FIG. 6. In the example, the UE maysearch the NR-DS for cell search or cell reselection, for example, basedon the periodicity of the NR-DS burst that is specified or configured bythe gNB.

In an example scenario where the NR-DS is used for a small celldiscontinuous transmission feature, the UE may perform small cellmeasurement by detecting NR-DS transmitted by small cells according topre-configured timing and resources locations. After detecting a cell(with valid cell ID), the UE may measure the signal strength based onthe cell specific reference signals (X-RS) used for discovery. The UEmay obtain the measured reference signal power (RSRP) or received signalstrength indicator (RSSI) from the X-RS. The measurement values can bereported to the gNB for its mobility handling, or may be used by the UEfor its autonomous mobility handling, or any other purpose as desired.

Turning now to physical broadcast channel (PBCH) design, with referenceto FIG. 7, a PBCH 702 may multiplex with the SS, for instance an SSS 704and a PSS 706, in a SS block 701. In addition, the PBCH 702 maymultiplex with SS within a same OFDM symbol as well. If a demodulationreference signal (DMRS) is used for PBCH demodulation, then the DMRSsequence may be generated by combining the two PN sequences, and theinitialized seed for the PN sequences can be a function of cell ID. IfUE is in the connected mode, for example, then the PBCH may not betransmit/multiplex within a SS block. The capability to turn on/off PBCHtransmission with SS in the connected mode can be configured via RRCsignaling or be dynamically configured via NR-PDCCH. In some cases, PBCHsymbols may be repeated to enhance the detection probability in a SSblock. If DMRS and PBCH is with symbol repetition, then the DMRS can beused for frequency offset estimation. An example PBCH design, inaccordance with an embodiment, is depicted in FIG. 7.

Turning now to paging channels, as used herein, a paging beam sweepingblock can be treated as a unit of beam sweeping time unit for pagingchannel during the idle mode. Each paging block may consist of at leastone or more CP-OFDM symbols. Multiple blocks can form a paging beamsweeping burst corresponding to a paging occasion (PO), which maycontaining a paging indication (PI). Here, the length of a sweepingburst refers to the number of paging beam sweeping blocks in a burst.Thus, a UE may receive a paging occasion with a paging indicationassociated with the synchronization signal block. As an example, if apaging beam sweeping burst length is equal to M, then there are Msweeping blocks existing in a PO. Since a paging may share the same beamburst structure as a synchronization signal (SS) block burst structure,the paging can share beams with the SS block. In FIG. 8, an example ofpaging sweeping burst with an SS block is depicted. The paging beamsweeping burst can be configured periodically or aperiodically, forinstance via a transmission. Each paging beam sweeping block can beassociated with a single beam or multiple beams, and the associationmethod can be with or without downlink control information (DCI).Furthermore, the paging may have different configurations. For example,if a paging does not involve any DCI indication, the beam associationmethod can be with the initial access channel, such as NR-PSS/NR-SSSand/or NR-PBCH. If there is a configured SS block burst for a UE at theconnected-mode, where it has a different setup than at the idle-mode SSblock burst, then this paging can share the same beam structure as theconfigured SS block at the connected-mode. As an example, referring toFIG. 8, there is a configured SS block burst for a UE at theconnected-mode, and the paging is associated with each SS block in thisconfigured SS burst. In accordance with the illustrated example, the POwith a paging indication and SS block can be frequency divisionmultiplexed (FDM) at the same OFDM symbols or time division multiplexed(TDM) at different OFDM symbols. TDM and FDM, between SS block andpaging cases, may be applied to the same beams. In another example, thePO resources for paging indication can be assigned via RRC signaling forsemi-static configuration.

Turning now to Synchronization Signal (SS) aspects, a PSS sequence caninclude (i) a Golay complement sequence; and (ii) sonar, modular sonar,or submodular sonar sequences. The NR-SS sequence can also include aNR-PSS that can have a structured signal pattern in the time-domain (TD)for fast compensation of frequency offset operations (CFO) acquisitionand peak detection. Here, the signal structured pattern design can takeplace within one OFDM symbol or multiple OFDM symbols. It can use TDsequences for NR-PSS. The signal structure pattern can be composed froma single sequence or multiple sequences

According to an embodiment, an example SS Burst Set is now described.Here, the SS bursts might not be evenly distributed across time if thereare higher priority channels that need to be scheduled and those higherpriority channels have allocated resources that overlap with SS burstresources. For example, URLLC physical control, data channel (URLLCPDCCH, PDSCH) might be scheduled with overlapping with the SS burst. Inthis case, the SS burst might be disabled for transmission.

According to another embodiment of the SS Burst Set, an example SS burstblock distribution in a burst set includes: (i) a consecutive burstblock; and (ii) a non-consecutive burst block. In the non-consecutiveburst block, in some examples, if all burst blocks in a burst arecontinuous allocated the in time-domain, then this type of burst can bereferred to as a consecutive burst block. Otherwise, the burst block canbe a non-consecutive burst block. Further, in some examples, if a burstlength for UE has been given (or assumed) in terms of an integer numberof OFDM symbols or number of sub-OFDM symbols, then the UE does not haveto assume that the burst block distribution consecutive. Thus, if a beamburst length (in terms of an integer M of symbols) is given for a UE,then the UE does not have to further assume whether the beam blocksinside the beam burst are consecutive or not. By way of example, if abeam burst has a duration equal to M=8 OFDM symbols, and the beam burstis composed of two beam blocks, each beam block in this beam burst uses2 OFDM symbols. Therefore, continuing with the example, there are fourempty OFDM symbols between two beam blocks in this example.

FIGS. 10 and 11 depicts examples of SS burst block distributions in aburst set. In the example depicted in FIG. 10, there are M=5 SS blocks1002 in one SS burst 1000, and each SS block 1002 has N=4 OFDM symbols1004. In this example, the SS burst has MN=20 OFDM symbols.

In an alternative example depicted in FIG. 11, there are M=5 SS blocks1102 in a SS burst 1100 and each SS block has N=4 OFDM symbols 1104, butit has reserved O=2 OFDM symbols 1106 between each burst block 1104. Insome cases, if the burst length is defined as MN+MO=20+10=30 symbols,then a given UE can detect the SS signal without knowing the burst blockdistribution in a given burst 1100. For example, if the burst length isknown to the UE in terms of number of OFDM or sub-OFDM symbols, then theUE is able to detect the SS without knowing the SS block distribution ina SS burst 1100.

Turning now to SS burst periodicity, in an example, the SS burstperiodicity impacts the timing-frequency acquisition time. If a SS burstperiodicity is set too long, it is recognized herein that the one-timedetection probability may need to be increased to avoid excessivesynchronization time.

In some cases, support of multi-beam transmission in a beam sweeping SSblock can reduce the beam sweeping time. If multi-beams are used in abeam sweeping block, in some examples, a beam ID signaling is required.For example, in a SS burst, if there are simultaneous multiple beamsthat are transmitted for NR-PSS, NR-SSS and NR-PBCH, then extra beamtraining reference signals can be used for distinguish them from eachother and/or signaling of beam IDs. The resource allocation for multiplebeams transmission of NR-PSS, NR-SSS and NR-PBCH can be the same ordifferent. For example, if two beams are transmitted simultaneously atthe same burst block time then, each beam may use different frequencydomain allocations or may share the same resources in frequency domainof burst block. In some examples, the beam reference signal can beconfigured as a function of Cell ID, beam ID, and/or SS burst timingindex. That is, the beam reference sequence can be initialized asfunction of c_(init)=f(N_(ID) ^(cell), n_(beam), n_(time-index)), wherec_(init) is the initialization of beam training sequence. The SS bursttiming/time index and beam IDs can be used for indicating physicalrandom access channel (PRACH) resources such as PRACH preamble signaland time-frequency allocation. In this way, it can avoid the detectionambiguity for a UE when there are simultaneous multiple beams that aretransmitted for NR-PSS, NR-SSS, and NR-PBCH. If there is a demodulationreference signal (DMRS) for the NR-PBCH demodulation in a SS burst, thenthe DMRS can be configured by Cell ID and/or with the SS burst timingindex, i.e., c_(init)=f(N_(ID) ^(cell), n_(time-index)), where c_(init)is the initialization of DMRS sequence.

In some cases, different nodes or gNBs might not transmit the samenumber of beams because some beams might not be transmitted in a SSburst among gNBs. In an example, if every gNB transmits the same numberof SS blocks in a SS burst, then a UE can still detect the SS frommultiple gNBs. Thus, in some cases, each gNB can configure the samenumber of SS blocks in a burst, but the decision to transmit beams ornot in a SS burst can be determined by gNB implementation.

Different transmission and receptions points (TRPs) can associate to thesame cell (gNB), and can use code division multiplexing (CDM) formultiple beam transmissions in a SS block, for example, to maintain beamorthogonality. Further, if a beam reference signal has been applied withan SS burst, then the beam reference signal can use CDM to maintain thebeam orthogonality.

Turning now to physical broadcast channels (PBCHs), in one example, theNR-PBCH carries a portion of the minimum system information (SI), suchas a master information block (NR-MIB), and secondary broadcast channelscarry the remaining minimum system information (RMSI). In some cases,the NR-PBCH can carry NR-MIB information and the resource indication ofremaining minimum system information (RMSI), for example, where the PRBsallocate the RMSI. For those secondary broadcast channel carrying theRMSI, the channels can share the SS burst set, thereby conserving beamsweeping resources. These secondary broadcast channels can be FDM withSS burst. Those broadcast channel resources and demodulation referencesignals can be indicated by the PBCH carrying NR-PBCH with minimum SIand MIB. In some cases, the broadcast channel that carry RMSI might notbe always transmitted. The demodulation reference signal can share thesame port as PBCH. The DMRS signal can be derived using various methods.In an example, if the beam ID is explicitly signaled for a SS burstblock, then the DMRS ID can be obtained via Cell ID, beam ID, and portID for a SS burst block. In another example, if the beam ID isimplicitly signaled by SS timing index from SS burst block, then theDMRS ID can be obtained via Cell ID, SS timing index, and port ID fromSS burst block.

Referring now to FIG. 12, in an example in which the NR-PBCH carries aportion of the minimum SI and the secondary broadcast channels carry theRMSI, those broadcast channels can be TDM with the SS burst 1202 in theinitial access. The secondary broadcast channels 1204 can share the sametransmission beams defined in the initial access SS burst 1202 a. Thosebroadcast channel resources and demodulation reference signals can beindicated by the PBCH with minimum SI and MIB as shown in FIG. 12. TheDMRS signal can be derived by using various mechanism. For example, ifthe beam ID is explicitly signaled from the SS burst block 1206 then theDMRS ID can be obtained via Cell ID, beam ID, and port ID from the SSburst block 1202. If the beam ID is implicitly signaled by the SS timingindex from the SS burst block 1206, then the DMRS ID can be obtained viaCell ID, SS timing index, and port ID from the SS burst block 1206.

Referring to FIG. 13, in another example in which the NR-PBCH carries aportion of the minimum SI and the secondary broadcast channels carry theRMSI, a beam refinement can be associated with a secondary broadcastchannel 1304 while carrying the RMSI. From a UE perspective, in someexamples, it can assume the transmission beams for those secondarybroadcast channels 1304 are based on a pre-configured SS burst set 1302in the initial access. Those broadcast channels 1304 can be transmittedvia a second level beam sweeping burst. The second level beam sweepingburst can employ finer beams than those coarse beams used in the initialaccess. For example, if those broadcast channel resources and thecorresponding refined beam sweeping burst information can be indicatedby the PBCH carrying minimum SI and MIB, then a given UE can perform asecond stage of beam training after successful detection of the NR-PBCHcarrying minimum SI and MIB, as shown in FIG. 13. In this case, the UEmay receive multiple broadcast channels that carry the same information.The UE can select the best signal to noise ratio (SNR) for the choosingthe refined beam for beam correspondence. In addition, those broadcastchannel can carry timing index information for implicit beam IDinformation. The DMRS signal can be derived using various mechanisms.For example, if the beam ID is explicitly signaling from a SS burstblock 1306 by using a beam training reference signal, then the DMRS IDcan be obtained via Cell ID, beam ID, and port ID from the SS burstblock 1306 (i.e., c_(init)=f(N_(ID) ^(cell), n_(beam), n_(time-index)),where c_(init) is the initialization of beam training sequence. If thebeam ID is implicitly signaled by the SS timing index from the SS burstblock 1306, then the DMRS ID can be obtained via Cell ID, SS timingindex, broadcast channel timing index, and port ID from a detected SSburst block 1306.

In another example PBCH design in accordance with another embodiment,the NR-PBCH can carry a portion of minimum SI, such as NR-MIB, and aphysical downlink shared channel (PDSCH) for new radio (NR-PDSCH) cancarry the RMSI. The NR-PDSCH resource and demodulation reference signals(e.g., such as ports and sequences) for carrying SI can be signaled viaa RACH response (RAR) message 4 with RRC connection setup. The DMRSsignal can be derived using various mechanisms. For example, if the beamID is explicitly signaled from the SS burst block, then the DMRS ID canbe obtained via Cell ID, beam ID, UE ID, and port ID from the RARmessage. In another example, if the beam ID is implicitly signaled bythe SS timing index from the SS burst block, then the DMRS ID can beobtained via Cell ID, SS timing index, UE ID, and port ID from the RARmessage.

In yet another example PBCH design in accordance with yet anotherembodiment, the NR-PBCH can carry a portion of minimum SI, such asNR-MIB, and a (cell-specific) physical downlink control channel (PDCCH)for NR (NR-PDCCH) can carry the RMSI. The NR-PDCCH resource (or searchspace) and the demodulation reference signals (such as ports andsequences) can be indicated by the PBCH carrying NR-PBCH with minimum SIand MIB. The demodulation reference signal for NR-PDCCH can beconfigured with the same or different beams in the SS burst set of theinitial access. A given UE may use the configured DMRS for demodulationof the NR-PDCCH as shown in FIG. 14, for example.

In some cases, the NR-PDCCH that carries the RMSI might not be alwaystransmitted. The DMRS signal can be derived using various mechanisms.For example, if the beam ID is explicitly signaled from the SS burst,then the DMRS ID can be obtained via Cell ID, beam ID, and port ID froma detected SS burst block. If the beam ID is implicitly signaled by SStiming index from a detected SS burst block, then the DMRS ID can beobtained via Cell ID, SS timing index and port ID from SS burst block.The NR-PDCCH search space can associate with beam ID and time-frequencyresources. The beam ID can be explicitly signaled via an extra beamreference signal, or it can be implicit signaling via the timing indexof the beam training sweeping burst. For example, referring to FIG. 14,in the initial access, the beam training sweeping burst can be the SSburst 1402 (or burst set). It can have its own beam sweeping burst setdefinition for NR-PDCCH. If NR-PDCCH has its own dedicated beam sweepingburst/burst set, then the NR-PDCCH may carry the timing index forimplicit beam ID signaling, or an extra beam reference signal can beused for beam ID indication, as shown on FIG. 14.

In an example, referring to FIG. 15, an NR-PDCCH 1502 can be transmittedvia multiple beams 1503 and search spaces 1504. This may allow a givenUE to monitor multiple different beams 1503 with its correspondingsearch space 1504 for beam tracking or beam recovery at the same time ordifferent times. The UE can track at least more than one NR-PDCCH searchspace 1504 for beam recovery. NR-PBCH timing indications may be implicitor explicit in which an SS burst timing index is signaled. In n example,the timing index can be used for masking CRC, or a bit-interleaver canbe used for the indication of timing index. A scrambling code can beused for the indication of timing index. The SS burst timing (time)index can be used for deriving the PRACH resources as well.

According to another aspect regarding random access, techniques aredescribed for RACH resource indication. Here, the PBCH may have adifferent period than SS burst when PRACH resources are signaled byPBCH. Techniques are also described for RACH RAR power boosting and beamreselection. When the UE retransmits the preamble but the RAR is notreceived, in some examples, a preamble can be reselected based on themonitored beams from the initial access (either from connected-mode oridle-mode SS). The RACH preamble may be selected from the resourcescorresponding to the best selected initial access DL beams. An exampleshowing DL initial access signals is shown in FIG. 16. In some examples,if it is still no RAR then UE can boost transmit power for PRACHtransmission when cycling the selected best M initial access beams (SSbursts) in a certain time window.

Example mechanisms for control channels are now described, in accordancewith various embodiments. Referring to FIG. 17, an example mini-slot isa scheduling or transmitting interval within a subframe and/or slot thatis defined with a reference numerology. A mini-slot may be used as,presented by way of example and without limitation, for:

-   -   Numerology specific signals, control and/or data. For example,        different subcarrier spacing and/or different symbol length may        exist within the reference numerology subframe and/or slot        (e.g., Mini-slot 1 and 2 in FIG. 17);    -   Beam specific signals, control, and/or data, e.g. resources        allocated to a specific narrow beam or beams (e.g., Mini-slot 6        and 7 in FIG. 17);    -   PHY function specific signals, control, and/or data, e.g. for a        specific or on-demand PHY function or procedure such as        synchronization in time and/or frequency or phase tracking;        broadcasting for system information or paging; beam management        (e.g., training, alignment or refining); radio link and/or        interference measurements; neighboring cell and/or TRP        discovery, etc. for a specific service or UE(s) (e.g., Mini-slot        8 and 9 in FIG. 17);    -   Service specific signals, control, and/or data, e.g. for URLLC        and/or mMTC service, and/or for services using grant-free UL        transmission (e.g., Mini-slot 1 and 2 in FIG. 17); and/or    -   UE or UE group specific signals, control and/or data, e.g.        self-contained to a specific UE or UE group (e.g., Mini-slot 3        and 4 and 5 in FIG. 17).

Example mini-slot configurations, as shown in Table 2 and Table 3 below,may be indicated, for example, statically via system information,semi-statically via RRC signal or MAC CE. Mini-slot configurations mayalso be indicated dynamically via the DL control channel (e.g., DCIs inDL Control of Subframe 1 or Slot 1 for Mini-slot 1, Mini-slot 2, andrepeated Mini-slot 3 and 4, DCIs in DL Control of Subframe 2 or Slot 2for repeated Mini-slot 3 and 4, and aggregated Mini-slot 5 and 6) withinthe subframe or slot of reference numerology, or the specific DL controlchannel within a mini-slot (e.g., Mini-DCIs in Mini-slot 5 indicatingthe aggregated Mini-slot 6 following Mini-slot 5), as shown in FIG. 18.DCIs or Mini-DCIs may contain mini-slot configuration parameters asdepicted in the example of Table 2, or a mini-slot configuration indexas depicted in the example of Table 3. It will be understood that thegaps illustrated in the figures, such as gaps 1802 in FIG. 18, unlessotherwise specified, may also be configured statically, semi-statically,or dynamically.

TABLE 2 Example of Mini-slot Configurations Configuration in FrequencyConfiguration in Time Offset Start Grid or Across (PRBs)- Pre- SymbolLength Aggregated Slot Length if partial Continuous Function empt Index(symbols) (optional) (optional) (PRBs) band (optional) (optional)(optional) e.g. e.g., e.g., 0: no e.g., e.g., 0: no e.g., 0: no 00: 1st00: n/a 000: 0 1: yes 000: full 000: 0 1: yes 00: sync 1: yes 01: 2nd01: 1 (no) band/ (no offset) 01: broadcast 10: 3rd 10: 2 001: 1 subband001: 1 10: control/data 11: 4th 11: 3 010: 2 001: 1 (repeat 1) 11:measure 011: 3 010: 2 010: 2 . . . 011: 3 011: 3 111: 7 . . . . . . 111:7 111: 7

TABLE 3 Example of Mini-slot Configuration Index Table Start Config.Symbol Length Grid or Across Length Offset Index Index (symbols)Aggregated Slot (PRBs) (PRBs) Function Pre-empt C₁ 00 001 000 0 000 00000 1 (1^(st)) (1) (no) (no) (full (no) (sync) (yes) band) C₂ 10 010 0000 110 100 01 1 (3^(rd)) (2) (no) (6) (4) (broadcast) (yes) . . . C_(i)01 011 100 1 000 000 10 0 (2^(nd)) (3) (repeat 4 (full (no) (control/(super- times) band) Data) position) . . .

Examples of mini-slot structures are illustrated in FIG. 19. It will beunderstood that hybrid automatic repeat request (HARQ) is used forpurposes of a closed-loop example, and similar mechanisms may be usedfor other operations, such as, for example, closed loop power control,CSI measurement, radio link adaptation, etc. As shown in FIG. 19, theMini-DCIs in Mini-slot 1 of Subframe i configures the mini gap and ULcontrol and/or data transmission(s); the Mini-DCIs in Mini-slot 2 ofSubframe i indicates the information for DL control and/or datatransmission(s); the Mini-UCIs in Mini-slot 5 of Subframe j indicatesthe UL control and/or data transmission(s); Mini-DCIs in Mini-slot 2 ofSubframe j indicates the DL control and/or data transmission(s). Also asexemplified in FIG. 19, the Mini-DCI for HARQ configuration of Mini-Slot2 of Subframe i configures either the ACK/NACK feedback for the receivedDL control, or data is transmitted on the Mini UL control of Mini-slot 2of Subframe i or Mini UL control of Mini-slot 5 of Subframe j.

Embodiments for transmitting URLLC over scheduled eMBB resources in theDL are now described in detail. When URLLC resources take precedenceover scheduled eMBB resources, there are various possibilities forallocating the URLLC time-frequency resources. For example, the URLLCtransmission may be super-positioned on top of the eMBB transmission, orthe URLLC transmission may alone be transmitted and no eMBB transmissionmay occur on those resources. Design aspects are also disclosed belowfor CB design and mapping for eMBB, MAC level recovery of affected eMBBinformation, and indicating scheduled or unscheduled transmissions tothe URLLC UE

In an example, the DL resources for a URLLC UE may be allocated in adistributed manner across a certain bandwidth or in a contiguous portionof the spectrum as seen in FIGS. 20A and 20B. Also, the resources may beconfined to a few symbols or less (e.g., as small as one) in time withrespect to the eMBB numerology to minimize the latency. It is recognizedherein that, in some cases, contiguous symbols in time may be mostbeneficial for URLLC. The resources may frequency hop across theallocated symbols as shown in FIG. 20C.

In an example embodiment, the reference signaling for URLLC UE to decodethe URLLC transmission may be shared with the eMBB transmission (e.g.,especially if eMBB and URLLC transmission use the same precoder), orseparate resources may be allocated for the URLLC transmission (e.g.,especially if the precoders are different from those of eMBB).

As mentioned above, the eMBB and URLLC transmissions may besuper-positioned within the same set of resources. In this case, in anexample, the relative power offset between the eMBB and URLLCtransmissions may be used to enable eMBB UE to recover its informationdespite the interference from the URLLC transmission. The eMBB may usesuccessive interference cancellation (SIC) to recover its information bydetecting the URLLC data and cancelling it from the received signal. TheeMBB UE is assumed to be signaled the information about the URLLCtransmission. The information may include, presented by way of exampleand without limitation, relative power of URLLC transmission withrespect to the eMBB transmission, code rate of URLLC transmission,modulation of the URLL transmission, and time and frequency resources ofthe URLLC transmission. In general, the solutions described above forindicating the URLLC information to the eMBB UE are also applicablehere.

Turning now to exclusive use of eMBB resources for URLLC, URLLC may betransmitted preemptively by redirecting the eMBB resources exclusivelyfor URLLC. This may impact the eMBB transmission. Example embodiments,which are described in detail below, enable eMBB systems to recover fromthe loss of resources in various scenarios, such as scenarios in whichthere is timely knowledge of pre-emptive URLLC transmission, delayedknowledge of pre-emptive URLLC transmission, or no knowledge of thepre-emptive URLLC transmission. It is noted that this scheme may beconsidered a special case of super-positioning in which the powerallocated to the eMBB is zero.

Timely knowledge of pre-emptive URLLC transmission is now described. TheDL signaling may explicitly or implicitly provide the eMBB UE knowledgeof the pre-emptive URLLC transmission before or during the reception ofthe eMBB TB. One or more of the following information may be conveyedimplicitly or explicitly to the UE about the pre-emptive URLLCtransmission, presented by way of example and without limitation:

-   -   Existence of a pre-emptive URLLC transmission    -   Impacted eMBB time-frequency resources such as, for example:        -   REs assigned to the URLLC transmission        -   RBs assigned to the URLLC transmission        -   CBs partially or fully assigned to the URLLC transmission        -   Symbols partially or fully assigned to the URLLC            transmission        -   Mini-slots or slots partially or fully assigned to the URLLC            transmission    -   One or more of the URLLC transmission parameters such as, for        example, modulation type, reference signal, transmission mode,        relative power level with respect to the eMBB transmission.

The knowledge of preempted resources may be signaled implicitly invarious ways. In one example, the eMBB and URLLC transmissions may usedifferent modulations. The eMBB UE may blindly detect the URLLCmodulation and exclude those resources from the eMBB TB. For example,the URLLC resources may be assigned in units of PRBs as shown in FIG. 2.The URLLC transmission may use the same (FIG. 21A) or differentnumerology (FIG. 21B) as the eMBB transmission. The URLLC transmissionis shown to occur in a mini-slot of 2 symbols with respect to the eMBBnumerology and its resources are allocated in chunks of PRBs distributedthrough the bandwidth. In some cases, the URLLC transmission may alsoinclude a control signaling region.

If an eMBB UE fails its CB or TB CRC check, in some cases, it mayblindly detect other modulations and permitted numerologies in each PRB.The eMBB UE may again decode the CB or TB such that the PRBs deemed tobelong to other modulations will be set to zero LLR in the LDPC decodingprocess, as shown in the example UE method depicted in FIG. 22.

Referring to FIG. 22, in accordance with the illustrated example at2202, an eMBB UE performs reception without knowledge of URLLCpreemption. At 2204, the eMBB UE decodes CB or TB by performing a CRCcheck for the CB or TB, respectively. If the CRC check is successful,the process proceed to 2205, where the UE sends an Ack. If the Step2205: If the eMBB UE has successful CRC check, it sends Ack. If the eMBBUE fails the CRC check, the process may proceed to 2206, where the UEchecks possible hypotheses for the presence of a URLLC preemption. At2208, the eMBB UE determines whether a URLLC preemption is detected. Ifno URLLC preemption is detected, the eMBB UE may send a Nack, at 2209.If eMBB UE detects a URLLC transmission, in accordance with the example,the UE zeros out the LLR for those resources and decodes the CB or TBagain, at 2210. At 2212, the eMBB UE determines whether there is a CRCmatch. If there is not a match, the process may proceed to 2213, wherethe eMBB UE sends a Nack. If there is a match, and thus the CRC issuccessful, the process may proceed to 2214, where the UE sends an Ack.Thus, in example cases in which the percentage of the preemptedresources is small or where the eMBB transmission has a low code rate,the eMBB UE may decode successfully after erasing the preempted LLRs(e.g., setting to zero).

In some cases, the set of modulations and numerologies to be blindlydetected may be configured through RRC signaling or through systeminformation.

In another example embodiment, a unique reference signal for URLLC maybe used to identify the URLLC transmission, as shown in FIG. 21. TheeMBB UE may correlate with the URLLC reference signal and detect a highcorrelation, and thus may identify corresponding resources as URLLCresources. The sequence for the URLLC reference signal may be specifiedor configured through system information or RRC as a function of one ormore of the following, presented by way of example and withoutlimitation:

-   -   Symbol within a mini-slot/slot/subframe/frame    -   RE within the bandwidth    -   Numerology of the eMBB transmission    -   Numerology of the URLLC transmission    -   Beam ID of the transmission    -   Cell ID    -   eMBB UE ID        An example of a corresponding UE procedure is shown in FIG. 23,        where the URLLC transmission's RS is used as an identifier to        indicate the associated URLLC resources.

Referring to FIG. 23, in accordance with the illustrated example, at2302, RS resources are used as identifiers to enable an eMBB UE todetect preemption. The eMBB UE may perform correlation of the receivedtransmission with expected RS sequences, so as to detect the presence ofthe RS associated with the preemption. When the eMBB UE cannot decodethe received CB or TB successfully, it may perform this operation todetermine if preemption resources are present. At 2304, the eMBB UEcomputes the correlation metric for the RS for candidate resources. Itcompares the metric with a threshold to determine if preemption isdetected or not. If the eMBB UE does not detect preemption (e.g., ifmetric is not higher than threshold), it may send a Nack, at 2305. Ifthe eMBB UE detects preempted resources, it sets the LLR of the receivedsymbols corresponding to those resources to zero, at 2306. At 2308, inaccordance with the illustrated example, the eMBB UE attempts to decodethe CB or TB again with updated LLRs, and thus determines whether CRCdetection is successful. If the eMBB UE does not have a successful CRCdetection, it transmits a Nack, at 2309. If the eMBB UE has a successfulCRC detection, it sends an Ack, at 2310.

Thus, as described herein, an apparatus may send a first transmissionand a second transmission, and the apparatus may assign resources of thefirst transmission to the second transmission, so as to preempt thefirst transmission with the second transmission. The apparatus may sendcontrol information so as to explicitly indicate that the secondtransmission should preempt the first transmission, and the controlinformation may further indicate at least one resource for preemption.Alternatively, the apparatus may transmit a reference signal thatindicates preemption information, so as to implicitly indicate that thesecond transmission should pre-empt the first transmission. The firsttransmission may be overwritten by the second transmission at selectresource locations of the first transmission. In some cases, asdescribed further below, the first transmission skips resources selectedfor preemption by the second transmission. Further, the apparatus maytransmit a control signal that indicates that the first transmissionshould be preempted by the second transmission. As described below, thecontrol signal can be transmitted in a mini-slot that also carries thesecond transmission. Alternatively, the control signal may betransmitted in subsequent slot to the mini-slot that carries the secondtransmission.

In yet another embodiment, different CRC masks are used for CBspreceding or following the preempted time-frequency resources. When a TBconsists of CBs similar to LTE, each CB may have a CRC check todetermine success or failure of the CB. It is proposed herein, inaccordance with an example embodiment, that the URLLC information beembedded in the CRC of the CB. For example, the CRC of one or more CBspreceding the CB or symbol being punctured by URLLC may be masked with asignature known a priori to the eMBB UE. If the eMBB UE detects a CRCfailure, it will detect that CB with the masking signature. If itpasses, it knows that the subsequent CB is punctured. Alternatively, oneor more CBs following the punctured CBs may be masked with the signatureindicating that the prior CB was punctured.

Turning now to indicating preempted resources explicitly to eMBB UE, inone embodiment, indication is through a Physical Preemption Indicationchannel (PPIC) in NR. For example, a PPIC may be designated to indicatethe URLLC transmission and its resources to the eMBB UE. The PPIC istransmitted when there is a URLLC transmission over eMBB. In some cases,the PPIC will not be transmitted if there is no URLLC transmission. Thisway, in some examples, no resources are wasted if there is no URLLCtransmission.

In an example, resources for the PPIC may be allocated in REs configuredfor the eMBB through standards or semi-statically through RRC ordynamically through its DCI making the DL eMBB grant. The location maycorrespond to N number of resources distributed through the eMBB's DLgrant.

The PPIC resources may occur in one or more symbols per slot and eachPPIC information may extend over one or more symbols. Each PPICinformation may provide indication of one or more preemptive URLLCtransmissions.

FIG. 24 shows examples of allocations of PPIC resources in differentscenarios. FIGS. 24A and 24B show localized and distributed PPICresources with one PPIC occasion actually carrying an indication of aURLLC transmission. The other PPIC resources are used for eMBBtransmission. FIG. 24C shows an example where two PPICs are transmittedindicating two URLLC transmissions. FIG. 24D shows an example where aPPIC may have resources distributed across multiple symbols.

In some cases, the eMBB UE may look for the PPIC on occasions when thePPIC is expected. Upon detecting the PPIC, it recognizes the resourcesfor the URLLC transmission. If it does not detect the PPIC, it continuesto decode the payload as if it does not contain the PPIC and URLLCtransmission.

The PPIC may contain one or more of the following information elementsabout the URLLC transmission, presented by way of example and withoutlimitation:

-   -   Symbol within a mini-slot/slot/subframe/frame    -   RE within the eMBB's DL grant or within some specified bandwidth    -   Numerology of the eMBB transmission    -   Numerology of the URLLC transmission    -   Reference signals for URLLC transmission    -   Beam ID of the transmission    -   Cell ID    -   eMBB UE ID

In some cases, the PPIC may use the same numerology as eMBB or have anumerology preconfigured through RRC or DCI of the eMBB grant. Themodulation for PPIC may be specified in the spec or configured throughRRC or DCI.

A CRC may be attached to PPIC information, and together they may beencoded with an error correction code. This CRC may be masked with eMBBUE ID-specific information.

In another embodiment, the presence and/or resources of the URLLCtransmission may be indicated through control signaling. This can bedone in multiple ways in accordance with various embodiments.

In one example, the control signaling region of the mini-slot carriesthe URLLC transmission. As shown in FIG. 25, the mini-slot carrying theURLLC transmission may have a control region that may indicate thepresence and resources for the preemptive URLLC transmission. The DCIscarried in the mini-slots control region are referred to as mDCI. Thiscontrol region's resources may be localized or distributed in frequencyor time and may be multiplexed with URLLC data.

The eMBB UE may be configured through the standard or RRC or its DCIabout the possible locations of the control regions for mini-slotsand/or the mini-slots. So the eMBB UE may check this controlinformation. In an example, if it finds valid control information, itrecognizes the resources of the URLLC transmission. If it does not findany, for example, it may assume that no URLLC transmission is preemptedon its DL grant.

The control region of the mini-slot may consist of multiple DCIs and theeMBB UE may have to blindly decode them to identify the DCI for theURLLC transmission. To minimize the number of blind decodes, the eMBB UEmay be required to monitor certain mini-slot locations may be valid andmini-slots may not occur at high periodicity such as every symbol.

An mDCI in the mini-slot may indicate to the eMBB UE the resources forthe URLLC transmission. This DCI may have the CRC be masked by the CellRadio Network Temporary Identifier (C-RNTI) of the eMBB UE. Another DCIin the mini-slot may indicate to the URLLC UE the presence of atransmission, its resources, and all parameters about that URLLC DLgrant. The DCI may have the CRC masked by the C-RNTI of the URLLC UE.FIG. 28 shows an example where there are two mDCIs in a mini-slot:mDCI-1 is intended for the eMBB UE and indicates the resources for theURLLC transmission, and mDCI-2 is intended for the URLLC UE andindicates the signaling parameters and resources to receive the DL URLLCgrant.

Alternatively, the control information may be encoded in a way that boththe eMBB UE and the URLLC UE may be able to share some or all of thecontrol information. For example, a portion of the URLLC controlinformation indicating the resources for the URLLC transmission may beencoded separately with a signature that both the eMBB and URLLC can useto decode. For instance, the CRC of this information may be masked witha signature configured for both the eMBB and URLLC UEs. This signaturemay be configured through RRC for both eMBB and URLLC UEs.Alternatively, the signature may be configured for the eMBB UE throughits DCI providing the DL grant and for the URLLC UE through theremaining part of the control information in the mini-slot. Thisremaining part of the DCI may also include other information specific tothe URLLC transmission such as, for example and without limitation:

-   -   Modulation    -   Code rate    -   Numerology    -   Precoder information    -   Beam ID    -   Reference signals

As shown in FIG. 27, an example mini-slot 2702 contains two mDCIs: amDCI-c that is common to eMBB and URLLC UE and indicates the resourcesof the preemptive URLLC transmission, and a mDIC-u that is URLLC UEspecific and provides other signaling information to URLLC UE concerningits DL grant.

In another example, a common control region may be designated in certainresources by NR. The eMBB UE may be configured to monitor one or moreoccasions of this common control region to look for a DCI indicating theURLLC transmission. Such a DCI may commonly indicate the resources forone or more URLLC transmissions. The eMBB UE will check to see if theindicated resources fall within in DL grant. If it finds URLLC resourceswithin its grant, the eMBB UE may account for puncturing.

In yet another example, the control region of themini-slot/slot/subframe may follow the URLLC transmission (e.g., seeFIG. 28). Here the eMBB UE may receive a DCI in the next mini-slot orslot or subframe that the eMBB is configured to monitor. This controlregion may provide a DCI indicating the presence of the URLLC resourcesin the past transmission. The eMBB UE may use the information toappropriately decode the eMBB data assuming that it has appropriatebuffering capabilities and can tolerate the increased latency.

Referring generally to FIG. 29, knowledge of the pre-emptive URLLCtransmission may be delayed in accordance with an example embodiment.For example, the eMBB UE may get knowledge of the preemptive URLLCtransmission after the eMBB TB has been processed, i.e., the eMBB UE isunable to process the payload again with this knowledge alone, possiblybecause of latency considerations. In this case, HARQ retransmission isone example way to recover from the resource loss. The HARQretransmission may include the resource locations of the URLLCtransmission (in the original transmission) at a fine or coarse level(in terms of actual REs or RBs or CBs or symbols) so that the eMBB UEcan discard the indicated portions prior to combining with theretransmission.

In an example case in which a retransmission is punctured by URLLCtransmission, and knowledge is not available in time at the eMBBreceiver, the recombined HARQ retransmissions may be corrupted. It isproposed herein that the NR-node either use timely information at leastfor retransmissions, or resend the information in a new HARQ process.

Turning now to code block (CB) design for eMBB, in LTE, the CBs aremapped to the resource grid in a frequency-first manner so that the codeblocks (CBs) can be decoded with minimal latency. For robustness topuncturing, in accordance with various example embodiments, the CBs inNR may be designed with the one of more of the following attributes,presented by way of example and without limitation. For example, CBs bemapped over more than one symbol. Frequency-first may be used. Thisensures, for example, that if a symbol is punctured for URLLC, the lossof resources is spread across a large number of CBs. The concept isexemplified in FIG. 30, where the CB₀ and CB₁ of a transport block (TB)are mapped in two symbols. In an example, CBs may be contained within Nnumber of symbols to keep the buffering and latency requirementsacceptable. For example, N may be restricted to the length of amini-slot, so that the impact of the puncturing affects only a limitedset of CBs, i.e. the code-blocks that falls in the region of themini-slot. If the amount of puncturing is significant, in some cases,this solution may ensure that at least some CBs may be decodedcorrectly.

In another example, after reserving the URLLC resources, the eMBB CBsmay be mapped to the resource grid in a contiguous manner. For example,the CBs may be mapped in a continuous manner on the available resources.In some cases, any loss of resources results in truncating the tail endof the payload. This may ensure that certain critical information, suchas the MAC CEs which are typically carried in the beginning of the eMBBpayload, will have less likelihood of being punctured. FIG. 31 shows anexample simplified illustration where an eMBB TB is made of CBs 0through 5. The symbols of the CBs are denoted by CB_(k, m) where kdenotes the CB number and m denotes the symbol number within that CB.FIG. 31A shows the mapping of the CBs to the available resource grid foreMBB. FIG. 31B shows an example where two symbols are punctured forURLLC resources. In this example, CB₂ and CB₃ data are lost to the eMBBUE. FIG. 31C shows an example where CB₂ and CB₃ are mapped after theURLLC resources are reserved. In the example process there are noresources available for CB₄ and CB₅, which cannot be transmitted.

Turning now to MAC level recovery of affected eMBB information, in somecases, when the puncturing from URLLC is so severe that it prevents theeMBB UE from decoding the TB or CB successfully, the UE may rely onretransmission of the punctured data. Ordinarily the retransmission ofthe punctured data may occur through a HARQ retransmission. Here anotherembodiment is disclosed to recover the punctured information. Instead ofa HARQ retransmission, the information bits corresponding to thepunctured data may be transmitted in a new HARQ process and the MAC willtake care of reassembling the information together. CBs that arepunctured may be transmitted in this manner through a new HARQ processand rely on MAC layer reordering of data.

In accordance with an example embodiment, the URLLC transmission may beprescheduled or unscheduled. When unscheduled, it may be preemptivelysent on eMBB resources and the solutions described above are applicable.

In some cases, the URLLC transmissions may also be prescheduled so thateMBB resources do not have to be punctured. For example, the DCI in thecontrol signaling region of a slot/mini-slot may indicate the DL grants.In this case, the control signaling region may be shared by both eMBBand URLLC UEs and the URLLC UE may blindly decode to identify its DCI.FIG. 32 shows an example where the control region of a slot carries DCIfor both eMBB and scheduled URLLC transmissions.

In yet another embodiment, a mini-slot may schedule the URLLC DL grant.In an example, eMBB resources might not be punctured as they mayterminate prior to the start of the mini-slot. Here, the URLLC UE maydecode the control region of the mini-slot to identify its grant asexemplified in FIG. 33, where the mini-slot is configured to have twosymbols and the control resources are multiplexed with data in the firstsymbol of the mini-slot. In an example, the URLLC UE is preconfiguredthrough RRC to monitor certain mini-slot occasions. When the URLLC UEdetects a DCI for it, it obtains the SL grant resources.

The control region of the mini-slot may have resources multiplexedbetween multiple URLLC UEs or eMBB UEs. In another example embodiment,semi-persistent configuration is provided to transmit URLLC, forexample, for regular and high traffic use cases. In this case, the RRCsignaling may set up a semi-persistent configuration indicating theresources and periodicity of reception, but the DCI may switch off or onthe semi-persistent DL grants for the URLLC UE.

As used herein, group common PDCCH refers to a channel that carriesinformation intended for a group of UEs. The group common PDCCH mayprovide various information to the UE, such as, for example: (i) Frameor slot structure (DL and UL portion, gap); (ii) Number of controlsignals; (iii) Starting location of data region; (iv) Numerology of oneor more PHY channels; (v) Bandwidth of operation for the UEs in thegroup. (A given UE may be configured to function within a limitedbandwidth for power savings and hardware efficiency. This bandwidth andits location may be indicated in the group-common PDCCH. This indicationmay be for the control signaling region or data region for DL and ULoperation. This indication for the control region may limit the numberof blind-decodes required to be performed by the UE); (vi) Structure ofmini-slots if any are present (number of mini-slots, number of symbolsin each); (vii) Paging indicator (indicates presence of a paging messageand/or the resources where the list of UEs being paged is transmitted);and (viii) Paging message (list of UEs being paged).

The modulation for the group-common PDCCH may be defined, for example asQPSK, such that UEs do not require an explicit indication to demodulateit.

In some cases, multiple group-common PDCCHs may be signaled, whereineach PDCCH may be received by UEs configured with the corresponding‘group common RNTI’ (gc-RNTI). A UE may have one or more gc-RNTIsconfigured. For example, a given UE may receive a paging message on onegroup common PDCCH and the slot structure on another PDCCH. gc-RNTIs maybe shared by UE of a particular use case such as URLLC or by UEscorresponding to a particular beam.

In some examples, the group common PDCCHs may be multiplexed in theavailable resources and the UEs may blindly decode them based on theirgc-RNTIs. In an example, the group-common PDCCH may be allocatedresources within the SS burst. As the beams sweep though the SS blocks,the beams may also sweep through the group common PDCCH. This example isshown in FIG. 34, where the SS burst contains SS blocks that are sweptthrough different beams. The SS block contains resources for the groupcommon PDCCH alongside resources for PSS, SSS, and PBCH.

The group common PDCCH may also be assigned in resources designated forDL control signaling, and may occur at a certain periodicity within aframe. FIG. 35 shows examples where the group common PDCCH has resourcesin the 0th and 5th subframes of a frame (FIG. 35A), and where the groupcommon PDCCH has resources only in the 0th subframe of the frame (FIG.35B). The periodicity for the group common PDCCH may bespecified/predetermined or may set up through the PBCH and semistatically updated. Furthermore, different beams may be used to signalthe symbols carrying group common PDCCH. In an example, the NR-PBCH mayindicate the presence of the group common PDDCH and the number andlocation of the resources for the group common PDCCH. In some cases, notall UEs are configured to receive a group-common PDCCH. In this case,for example, the relevant configuration information may be signaled inthe common control search space or UE-specific search space.

Turning now to the physical uplink control channel (PUCCH), in someexamples, resources for short duration PUCCH may be assigned anywherewithin the available spectrum. Especially for UL using CP-OFDM waveform,as there is no constraint of using contiguous REs, the short PUCCH mayhave resources distributed in the spectrum.

FIG. 36 shows different example ways of assigning resources for shortPUCCH in a DL centric slot. Here the leading symbols carry resources forthe DL. The UCI is sent on one (FIG. 36B) or two (FIG. 36A) of the ULsymbols occurring at the end of the slot. The UCI may be multiplexedwith data (FIG. 36C). The UCI may have frequency hopping between symbols(FIG. 36D). The UCI may give contiguous or dis-contiguous resources, forexample, especially if deployed with CP-OFDM (FIG. 36E).

FIG. 37 shows different ways of assigning resources for short PUCCH in aUL centric slot. In an example, one or two symbols may be used to carrythe UCI and the resources may be present at the start of the ULsignaling region (FIG. 37A) or at the end of the UL signaling region(FIG. 37B). The UCI resources may be discontinuous especially withCP-OFDM (FIG. 37C) or the resources may frequency hop between symbols(FIG. 37D).

In some examples, the DCI makes the DL grant implicitly or explicitlyindicates resources for the short PUCCH. Also, within the UCI resources,one or more UEs may be code division multiplexed or time divisionmultiplexed or frequency division multiplexed.

Turning now to PUCCH in Long Duration, in some examples, because longPUCCH is a good candidate for UEs that are UL power limited (e.g., thosein the cell edge), long PUCCH may operate using DFT-s-OFDM. Resourcesmay be reserved in specific frequency bands for long PUCCH similar tothe resources at band edge for PUCCH in LTE. FIG. 37 shows an example ofhow resources may be reserved for long PUCCH in the spectrum. Here, 3“PUCCH-bands” are reserved for long PUCCH signaling. A UE may beallocated resources from one of more of these PUCCH-bands and frequencyhopping between the PUCCH-bands may be used across symbols/mini-slots orslots to improve frequency diversity. Depending on the maximum bandwidththat the UE can process, the NR-Node may configure a subset of adjacentPUCCH-bands for it to receive it long format PUCCH. This configurationmay be done semi-statically through RRC or dynamically through DCI.

FIG. 39 shows an example of how the resources may hop for long PUCCH. Inaccordance with the example, different UEs are assigned resources ondifferent PUCCH bands. UE1 operates on PUCCH bands 0 and 1 and hopsbetween them. UE2 operates on PUCCH bands 1 and 2 and hops between them.UE3 operates on all the 3 PUCCH bands.

The hopping pattern may be tied to one or more of the following: (i)cell ID; (ii) beam ID of the associated DCI (making the grant orreserving the UCI resources); (iii) beam ID of the resources of the UCI;(iv) C-RNTI; and (v) Symbol/mini-slot/slot number in a subframe.

In some cases, a UE may be semi-statically configured to use short PUCCHor long PUCCH. In addition, a dynamic override may be provided for sothat the short or long PUCCH configuration may be dynamically changedfor the grants corresponding to that DCI.

Turning now to HARQ mechanisms, described herein is a multi-bit A/Nscheme, wherein more than 1 bit of A/N is transmitted by the UE inresponse to reception of a TB. The TB may be composed of multiple CBs.Similar to LTE, the CBs may be encoded with a CRC. The UE may transmitA/N for one or more of the decoded CRCs within the TB.

FIG. 40 shows an example in which the CBs in a TB are grouped intomultiple groups and one A/N bit is transmitted per group. For example,when URLLC is preemptively transmitted over eMBB, the eMBB UE may beconfigured to report multi-bit A/N. The multiple bits in this A/N reportmay consist of single-bit A/N response for each CB or a group of CBsthat are impacted by the URLLC. An example is shown in FIG. 40 where apreemptive URLLC transmission punctures some REs of an eMBB UE in CB0,CB1, and CB2. In this case, the eMBB UE may be configured to reportricher A/N by reporting in one of the following ways, presented by wayof example: (i) A/N per CB of the TB; (ii) One A/N for TB, one A/N forthe group {CB0, CB1 and CB2} of CBs; (iii) One A/N for TB, one A/N foreach of CB0, CB1 and CB2; and (iv) One A/N for TB, one for group {CB1,CB2}, one for CB0 (a good configuration to choose if the impact ofpuncturing is very sever on CB0 and less severe on CB1 and CB2).

Referring now to FIG. 41, URLLC may puncture eMBB transmissions suchthat CB0, CB1, and CB2 of eMBB payload are affected. The number of A/Nbits to transmit and information on how they may be CBs may beconfigured by the NR-Node, for example, depending on the traffic and usecase. In some examples, the configuration may be made semi-statically ordynamically through a DCI. For example, the NR-PDCCH carryinginformation on the TB's HARQ process or A/N resource allocation mayindicate the number of A/N bits per TB.

It is recognized herein that the HARQ procedure may need to handlemultiple numerologies and TTI lengths. In some examples, HARQretransmission may occur in numerologies and TTI lengths different fromthe original transmission. FIG. 42 shows an example where theretransmission occurs on a shorter TTI of a different numerology. Insome cases, different HARQ processes with different numerologies and TIlengths may be configured for a UE. An example use case for such aconfiguration is one where some HARQ processes cater to eMBB while somecater to URLLC for the same UE.

Turning now to packet duplication in NR-PDCP, in an example, a packetmay be duplicated in the NR-PDCP and the copies may be transmitted overdifferent carriers in the case of carrier aggregation. It is recognizedherein that this may improve reliability for the UE. For example, the UEmay receive multiple copies of that packet and keep the one that iserror-free. If the UE fails to correctly decode all of the copies, insome cases, it may transmit A/N corresponding to all of the componentcarriers that served the packet or only a subset of them, for example,only on the primary component carrier. In accordance with an example,duplicate packets may also be transmitted via different beams comingfrom a single or different TRPs.

Turning now to UE capability indications, in some cases, the timingdepends on the TB payload size (this determines the processing time,especially for channel estimator and LDPC decoder), use case (forexample, URLLC requires very short interval), and the UE capability (forexample, mMTC UEs may have slower processing capabilities). In anexample, the UE is required to indicate its capability of minimum HARQprocessing time to the NR-Node. The UE indicate its capability toNR-Node by signaling various information. For example, the informationmay include average time required to process TBs of sizes S1, S2, . . .Sn, where n=>1 after reception of relevant data, reference and controlsignals. The time may be indicated as a metric from a pre-defined scaleof numbers. The UE may be calibrated for such information and programmedwith this information for different carrier frequencies and samplingfrequencies. Maximum supported sampling frequency. The UE may indicateto the NR-Node the highest sampling frequency it can support. Theindication itself may happen through UL RRC and may be semi-staticallyconfigured. For example, if the UE moves to a different carrierfrequency band, it may reconfigure its capabilities for that frequencyband.

When a UE powers up and connects to a cell for the first time, it maytransmit its A/N by default at some specified latency with respect to aDL reception. Alternatively, the NR-Node may configure it to transmitit's A/N at a high but acceptable latency. Subsequently, the UEindicates its processing capabilities in an UL transmission after whichthe NR-Node may configure the A/N latency suitably in a dynamic orsemi-static manner.

Another way to inform the NR-Node of the UE capabilities is at the timeof performing a RACH procedure. The RACH resources may be partitionedinto groups such that each group indicates a certain UE capability forA/N latency. The UE's choice of RACH resource indicates it capability tothe NR-Node. Alternatively, the UE may piggyback a message with thePRACH to indicate its capabilities or include its capability informationin the messaging of the RACH procedure.

Turning now to URLLC transmissions, the NR-DCI of URLLC UE may bedesigned in a compact manner so that with required aggregation level(code rate), the resource requirement for NR-PDCCH can be kept small,thereby also facilitating easier blind decoding. The HARQ informationmay be provided in a compact manner. The starting PRB location may beassociated with the HARQ process ID and does not need explicitsignaling. Information about the DMRS such as the code and resources mayalso be implicitly tied to some other information, such as the startingPRB number for example.

URLLC may be limited to support only a subset of modulations (forexample QPSK only) to support high reliability. This may reduce oreliminate the need to signal the modulation type. In some cases, TPCcommands are not sent as part of a grant allocation to a URLLC UE. TheTPC commands may be transmitted separately to the URLLC UE on adifferent DCI format that might not necessarily conform to highreliability and low latency.

According to the present application, it is understood that any or allof the systems, methods and processes described herein may be embodiedin the form of computer executable instructions, e.g., program code,stored on a computer-readable storage medium which instructions, whenexecuted by a machine, such as a computer, server, M2M terminal device,M2M gateway device, transit device or the like, perform and/or implementthe systems, methods and processes described herein. Specifically, anyof the steps, operations or functions described above may be implementedin the form of such computer executable instructions. Computer readablestorage media includes volatile and nonvolatile, removable andnon-removable media implemented in any method or technology for storageof information, but such computer readable storage media do not includessignals. Computer readable storage media include, but are not limitedto, RAM, ROM, EEPROM, flash memory or other memory technology, CD ROM,digital versatile disks (DVD) or other optical disk storage, magneticcassettes, magnetic tape, magnetic disk storage or other magneticstorage devices, or any other physical medium which can be used to storethe desired information and which can be accessed by a computer.

According to yet another aspect of the application, a non-transitorycomputer-readable or executable storage medium for storingcomputer-readable or executable instructions is disclosed. The mediummay include one or more computer-executable instructions such asdisclosed above in one of the plural call flows. The computer executableinstructions may be stored in a memory and executed by a processordisclosed below in FIG. 47B, and employed in devices including UE,NR-Node, and TRP/RRH. In one embodiment, a computer-implemented UEhaving a non-transitory memory and processor operably coupled thereto,as described below in FIG. 47B is disclosed. The UE includes anon-transitory memory having instructions stored thereon for performinga beam recovery process. The UE also includes a processor, operablycoupled to the non-transitory memory. The processor is configured toperform the instructions of providing a trigger for a serving beam toinitiate the beam recovery process. The processor is also configured toperform the instructions of detecting an occurrence of the trigger forthe serving beam. The processor is also configured to perform theinstructions of performing a beam management protocol based on thedetected occurrence of the trigger for the serving beam. Further, theprocessor is configured to perform the instructions of terminating thebeam recovery process.

Turning now to beamforming training that can reduce the latency for thebeamforming training processing time, described now is an examplebeamforming training sequence design, which can mitigate theinterference from other TRPs or other beams from the same TRP. Anexample procedure to detect the desired beam and a new DoD estimationmethod are also described.

Consider a MIMO-OFDM beamforming system with K subcarriers, where thetransmitter and receiver are equipped with N_(t) transmit antennas andN_(r) receive antennas, respectively. At the transmitter, a beamformingvector v is applied for a beam sweeping OFDM symbol, which is selectedfrom a predesigned codebook. Here, we define a beam sweeping block canbe treated as a unit of beam sweeping time unit for broadcasting beamtraining OFDM symbols. Each beam sweeping block may consist of one ofmultiple OFDM symbols. Multiple beaming blocks can form a beam sweepingburst. The length of a sweeping burst refers to the number of beamsweeping blocks in a beam sweeping burst, i.e., a beam sweeping burstlength is equal to N then there are N sweeping blocks in a sweeping beamburst. In FIG. 43, an example of a sweeping burst is depicted. In thisexample, there are N=12 beam blocks in a beam sweeping burst and eachbeam block is equal to one OFDM symbol. At each beam sweeping block, ittransmit a training beam pattern. Each training beam is associated witha unique training sequence. The Zadoff-Chu (ZC) training sequence isadopted as the beam training sequence. The ZC sequence has been widelyused in LTE systems as DL synchronization sequence, UL random accesschannel, demodulation reference and sounding reference signal. There areseveral advantages to use ZC sequence as beam training sequences. Forexample, the ZC sequence has low PAPR property. Further, the ZC sequencewith a same root but with different cyclic-shifts can form multipleorthogonal training sequences. In an example described herein, this kindof orthogonal property is adopted for mitigating other interferingtraining beams.

At the receiver, the received signal at the q-th receive antenna at thek-th subcarrier may be expressed as:

y _(q)(k)=H _(q) ⁽⁰⁾(k)v ⁽⁰⁾ s ₀(k)+Σ_(i=1) ^(M) H _(q) ^((i))(k)v^((i)) s _(i)(k)+n _(q)(k),

where for i=0, 1 . . . M, H_(q) ^((i))(k), v^((i)) and s_(i)(k) are the1×N_(t) channel vector at the k-th subcarrier between the i-th transmitand the q-th receive antenna at the receiver, the beamforming matrix ofthe i-th eNB, and the transmit symbol of the i-th transmit at the k-thsubcarrier, respectively. Note that the interference could come from thesame TRP using different beams. In practice, the maximum channel delayspread L≤L_(cp), where L_(cp) denotes the OFDM cyclic prefix length.Without losing the generality, we assume that s₀(k) is the desiredtraining sequence at subcarrier k and s_(i)(k), i=1, 2, . . . , M, areother interfering training beams. By collecting all subcarriers, thereceived signal in frequency domain can be obtained,

${y_{q} = {\begin{bmatrix}{y_{q}(0)} \\{y_{q}(1)} \\\vdots \\{y_{q}( {K - 1} )}\end{bmatrix} = {{\sum_{i = 0}^{M}{{\overset{\sim}{H}}_{q}^{(i)} \cdot \begin{bmatrix}{s_{i}(0)} \\{s_{i}(1)} \\\vdots \\{s_{i}( {K - 1} )}\end{bmatrix}}} + \begin{bmatrix}{n(0)} \\{n(1)} \\\vdots \\{n( {K - 1} )}\end{bmatrix}}}},$

where {tilde over (H)}_(q) ^((i)) is the diagonal matrix as follows,

${\overset{\sim}{H}}_{q}^{(i)} = \begin{bmatrix}{{H_{q}^{(i)}(0)}v^{(i)}} & 0 & \ldots & 0 \\0 & {{H_{q}^{(i)}(1)}v^{(i)}} & \ldots & 0 \\\vdots & \vdots & \ddots & \vdots \\0 & 0 & \ldots & {{H_{q}^{(i)}( {K - 1} )}v^{(i)}}\end{bmatrix}$

It can also be rewritten as

$\begin{matrix}{{y_{q} = {{S^{(0)}B_{q}^{(0)}} + {\sum_{i = 0}^{M}{S^{(i)}B_{q}^{(i)}}} + n_{q}}},} & (1) \\{where} & \; \\{S^{(i)} = \begin{bmatrix}{s_{i}(0)} & 0 & \ldots & 0 \\0 & {s^{(i)}(1)} & \ldots & 0 \\\vdots & \vdots & \ddots & \vdots \\0 & 0 & \ldots & {s_{i}( {K - 1} )}\end{bmatrix}} & \; \\{B_{q}^{(i)} = {{\begin{bmatrix}{{H_{q}^{(i)}(0)}v^{(i)}} \\{{H_{q}^{(i)}(1)}v^{(i)}} \\\vdots \\{{H_{q}^{(i)}( {K - 1} )}v^{(i)}}\end{bmatrix}\mspace{14mu} {and}\mspace{14mu} n} = {\begin{bmatrix}{n(0)} \\{n(1)} \\\vdots \\{n( {K - 1} )}\end{bmatrix}.}}} & \;\end{matrix}$

Let H_(qp) ^((i)) be the frequency domain channel response between thep-th transmit antenna at the i-th eNB and the the q-th receive antenna,

H _(qp) ^((i))=[H _(qp) ^((i))(0)H _(qp) ^((i))(1) . . . H _(qp)^((i))(K−1)]^(T).

With these notations, the channel vector B q can be rewritten as:

$\begin{matrix}{B_{q}^{(i)} = {\lbrack \begin{matrix}{\begin{bmatrix}{H_{q\; 1}^{(i)}(0)} & \ldots & {H_{{qN}_{t}}^{(i)}(0)}\end{bmatrix}v} \\{\begin{bmatrix}{H_{q\; 1}^{(i)}(1)} & \ldots & {H_{{qN}_{t}}^{(i)}(1)}\end{bmatrix}v} \\\vdots \\{\begin{bmatrix}{H_{q\; 1}^{(i)}( {K - 1} )} & \ldots & {H_{{qN}_{t}}^{(i)}( {K - 1} )}\end{bmatrix}v}\end{matrix} \rbrack = {\quad{\lbrack \begin{matrix}H_{q\; 1}^{(i)} & H_{q\; 2}^{(i)} & \ldots & H_{{qN}_{t}}^{(i)}\end{matrix} \rbrack \cdot {v.}}}}} & (2)\end{matrix}$

The channel vector H_(qp) ^((i)) can be derived from the time domainchannel response between the p-th transmit antenna at the i-th eNB andthe the q-th receive antenna h_(qp) ^((i)),

H _(qp) ^((i)) =Fh _(qp) ^((i))  (3)

where F denotes the K×K DFT matrix and h_(qp) ^((i))=[h_(qp) ^((i))(0) .. . h_(qp) ^((i))(L−1) 0 . . . 0]^(T), where h_(qp) ^((i))(i), i=0, . .. , L−1, the time domain channel taps. By substituting (3) into (2), wehave

B _(q) ^((i)) =D[h _(q1) ^((i)) h _(q2) ^((i)) . . . h _(qN) _(t)^((i))]v=Fĥ _(q) ^((i))

where ĥ_(q) ^((i))=[h_(q1) ^((i)) h_(q) ^((i)) . . . h_(qN) _(t)^((i))]_(v) is the time domain effective channel. By substituting theabove equation into (1), we obtain the received frequency-domain signalvector at the q-th received antenna can be expressed as

y _(q) =S ⁽⁰⁾ Fĥ _(q) ⁽⁰⁾+Σ_(i=1) ^(M) S ^((i)) Fĥ _(q) ^((i)) +n_(q).  (4)

To distinguish the desired beam from the interference beams, inaccordance with an example, a ZC sequence is applied to the referencesignals as follows: s⁽⁰⁾=[s₀(0), s₀(1), . . . , s₀(K−1)]^(T) is theK-length ZC sequence, and s^((i)) the cyclic shift sequence,s^((i))=C_(i)s⁽⁰⁾, where

$c_{i} = {{diag}( {1,e^{2\pi \; j\frac{ic}{K}},e^{2\pi \; j\frac{2{ic}}{K}},\mspace{11mu} \ldots \mspace{14mu},e^{2\pi \; j\frac{{({K - 1})}{ic}}{K}}} )}$

and c is the cyclic shift. Thus, the reference sequences of the adjacentbeams are different cyclic shifted versions of the same ZC sequence. Asshown below, the interference caused by those adjacent beams could beseparated from the time domain signals.By substituting the above equation to (4), we have:

y _(q) =S ⁽⁰⁾ Fĥ _(q) ⁽⁰⁾ +S ⁽⁰⁾Σ_(i=1) ^(M) C _(i) Fĥ _(q) ^((i)) +n_(q).  (5)

Note that C_(i)Fĥ_(q) ^((i))=Fh̆_(q) ^((i)) where h̆_(q) ^((i)) is thecyclic shift of the original ĥ_(q) ^((i)) by ic. Then we have

y _(q) =S ⁽⁰⁾ Fĥ _(q) ⁽⁰⁾ +S ⁽⁰⁾Σ_(i=1) ^(M) Fh̆ _(q) ^((i)) +n_(q).  (6)

Let the matrix D be the inverse of S⁽⁰⁾F, and then we have the timedomain signals

Z _(q) =Dy _(q) =ĥ _(q) ⁽⁰⁾+Σ_(i=1) ^(M) h̆ _(q) ^((i)) +Dn _(q).  (7)

As long as the cyclic shift c is greater than the time spread L, theeffective channel

${\hat{h}}_{q}^{(0)} = {\begin{bmatrix}{h_{q\; 1}^{(0)}(0)} & \ldots & {h_{{qN}_{t}}^{(0)}(0)} \\{h_{q\; 1}^{(0)}(1)} & \ldots & {h_{{qN}_{t}}^{(0)}(1)} \\\vdots & \vdots & \vdots \\{h_{q\; 1}^{(0)}( {L - 1} )} & \ldots & {h_{{qN}_{t}}^{(0)}( {L - 1} )} \\0 & \ldots & 0 \\\vdots & \vdots & \vdots \\0 & \ldots & 0\end{bmatrix}{v.}}$

can be estimated from the first L rows of Z_(q) without affected by theinterference. By reorganizing the entries of (7), we have

$x_{l} = {\begin{bmatrix}{z_{1}\lbrack l\rbrack} \\{z_{2}\lbrack l\rbrack} \\\vdots \\{z_{N_{r}}\lbrack l\rbrack}\end{bmatrix} = {{\begin{bmatrix}{h_{11}^{(0)}(l)} & {h_{12}^{(0)}(l)} & \ldots & {h_{1N_{t}}^{(0)}(l)} \\{h_{21}^{(0)}(l)} & {h_{22}^{(0)}(l)} & \ldots & {h_{2N_{t}}^{(0)}(l)} \\\vdots & \vdots & \vdots & \vdots \\{h_{N_{r}1}^{(0)}(l)} & {h_{N_{r}2}^{(0)}(l)} & \ldots & {h_{N_{r}N_{t}}^{(0)}(l)}\end{bmatrix}v} +}}$

for each path l, l=0, 1, . . . , L−1, i.e.,

x _(l) =H _(l) v+

.  (8)

The example beam detection method can be summarized using the followingsteps, in accordance with an example embodiment, though it will beunderstood that the list below is presented by way of example, and notby way of limitation:

-   -   1. For a transmitter, an ID is assigned to each beam, which        determines not only a ZC sequence but also point to an index of        the beamforming vector v selected from a predesigned codebook.    -   2. Training sequence design:        -   a. For interference beams from other TRPs: In each beam            sweeping block, the beam reference signals from different            transmitters are based on a ZC sequence with a same root but            with different cyclic-shifts: 0, c, 2c, . . . , moduled by            K, where c is greater than the maximum channel delay spread            L and c=K/N, where N is an integer. The cyclic-shifts are            assigned to each transmitter, and known by the receivers.        -   b. For interference beams from the same TRP: In each beam            sweeping block, multiple beams from the same TRP could be            transmitted, whose training sequences are based on a ZC            sequence with a same root but with different cyclic-shifts:            0, c, 2c, . . . , moduled by K, where c is greater than the            maximum channel delay spread L and c=K/N, where N is an            integer. The adjacent beams should be assigned different            cyclic shifts to mitigate the interference. For example, the            beamforming codebook could use DFT beams with the size of 8.            A ZC sequence of the length of 32 is chosen for the beam            training sequence, and the cyclic-shift for the training            sequence could be set to c=8. The beams could be assigned            cyclic-shifts clockwise or counter clockwise by 0, c, 2c, .            . . , moduled by K. Then the adjacent beams have different            cyclic-shifts, which may guarantee that the interference            could be canceled. The beams assigned the same cyclic-shift            are separated by a large angle, so that the interference            could be ignored.    -   3. For each beam sweeping block, from the time domain received        signals, the receiver obtains the frequency domain signal y_(q);    -   4. For each possible reference signal sequence, multiply each        subcarrier of y_(q) by the inverse of the reference signal, and        then apply the IFFT to obtain the time domain signal Z_(q);    -   5. Select the first L rows of Z_(q) to cancel the interference        from other transmitters and calculate the energy

Σ_(l=0) ^(L−1) |Z _(q)[l]²  (9)

-   -   6. Repeat Step 4 and 5 for all possible reference signal        sequences, and find the reference signal sequence with the        maximum energy (9). Obtain the beam ID from the detected        reference signal sequence as the beam ID for the current beam        sweeping block.    -   7. Repeat Step 3 to 6 for all beam sweeping blocks, and find the        two beam sweeping blocks with the largest and the second largest        energy (9).    -   8. Obtain the best Q beamforming vectors, for example, Q=2, v₁,        v₂ from the associated beam IDs of beam sweeping blocks.

Once the best two training beams are identified, it can proceed toestimate the DoA and DoD of the channel. Here, it is assumed that thechannel at the l-th tap, l=1, . . . , L can be expressed as

H _(l)=α_(l) a _(r,l) a _(t,t) ^(H),  (10)

where a_(r,l)=[1 e^(j2πθ) ^(l) e^(j2π2θ) ^(l) . . . e^(j2π(N) ^(r)^(−1)θ) ^(l) ^(]T), a_(t,l)=[1 e^(j2πφ) ^(l) e^(j2π2φ) ^(l) . . .e^(j2π(N) ^(t) ^(−1)φ) ^(l) ^(]T) and α_(l)∈

is the channel complex gain. The φ_(l) and θ_(l) denotes the channel ofangel of departure and angle of arrival, respectively. From Eq. (8) andEq. (10), the Eq. (8) can be rewritten as

x _(l)=α_(l) a _(r,l) a _(t,l) ^(H) v+

.  (11)

Furthermore, the Eq. (11) can be expressed as

x _(l) =a _(l)(v ^(T) ⊗I _(N) _(r) )vec(a _(r,l) a _(t,l) ^(H))+vec(

),  (12)

where ⊗ denotes the kronecker product matrix operator, I_(N) _(r) is theidentity matrix with size of N_(r) and vec(⋅) is the matrix to vectoroperation. The estimation of the DoD (i.e., φ_(l)) of the channel can beexpressed as

$\begin{matrix}{{{\min\limits_{d}{d}_{1}},{{subject}\mspace{14mu} {to}}}{{{\sum_{i = 1}^{2}{{{{( {v_{i}^{T} \otimes I_{N_{r}}} ){Ad}} - x_{l}}}}_{2}^{2}} \leq ɛ},}} & (13)\end{matrix}$

where v₁ and v₂ are the beamforming vectors obtained from the Step 8 andthe dictionary matrix A is formed by the following method:

A=[a ₁ a ₂ . . . a _(N) _(φ) _(N) _(θ) ],

where

a _(i) =a _((α−1)N) _(φ) _(+β)=(b(αΔφ))*⊗c(βΔθ),  (14)

where N_(φ) is the dictionary length and Δφ is the resolution for DoD;N_(θ) is the dictionary length and Δζ is the resolution for DoA,respectively.

$\begin{matrix}{{{b(\vartheta)} = \begin{bmatrix}1 & e^{j\; 2{\pi\vartheta}} & \ldots & e^{j\; 2{\pi {({N_{t} - 1})}}\vartheta}\end{bmatrix}^{T}}{{c(\vartheta)} = {\begin{bmatrix}1 & e^{j\; 2{\pi\vartheta}} & \ldots & e^{j\; 2{\pi {({N_{r} - 1})}}\vartheta}\end{bmatrix}^{T}.}}} & (15)\end{matrix}$

Since the solution d∈

^(N) ^(φ) ^(N) ^(θ) ^(×1) is a sparse solution in matrix A, this kind ofsolution for Eq. (13) can use least absolute shrinkage and selectionmethod (also call LASSO method) to solve it. Once it obtains the DoD ofthe channel then the DoD can be used as feedback for transmitter to use.

-   -   9. The detected best Q beam IDs with or without estimated DoD        can be used for feedback to the transmitter. The transmitter can        use the estimated DoD for beam refinement without using beam        sweeping method for beam refinement.

Turning now to examples for Beam Management, multiple beams may be usedto provide a relatively large cell coverage area. Due to UE mobility,beam quality and/or availability between a UE and the network may changefrequently, even when the UE rotates a little bit. Beam tracking andswitching mechanisms are typically applied to select and re-selectproper beams (e.g., beams with adequate quality, such as with RSRP orRSRQ above certain threshold) among a set of available beams, so thatthe link connection between UE and network can be maintained. However,in some cases of sudden beam quality drop, those regular beam trackingand switching mechanisms are not enough. For example, beam qualitydegrades fast for fast moving UE, and there are no enough time budgetsto perform beam switching. Or network may not schedule enough resourcesto perform beam switching and re-alignment. Or sudden changes happen inradio environments, such as moving obstacles caused beam blockage.

Without proper beam recovery mechanisms, if the aforementioned suddenbeam quality drop persists, radio link failure (RLF) as in legacy LTEnetworks may be declared When RLF is declared, the UE may performconnection re-establishment and cell selection may be initiated, whichcan cause a significant amount of network signaling, latency, connectioninterruptions, and power consumption. In addition, in HF-NR, degradedbeam quality may rebound back soon, or/and there may be other easyalternative beams available. Therefore, declarations of RLF might not benecessary and should be minimized, in some cases.

Based on these considerations, among others, in some cases, beam recoverprocesses should perform after and when regular beam tracking andswitching processes are not able to maintain link connection, but beforeRLF is declared. If the beam recover process fails anyway (e.g., noalternative beams to recover link connections), RLF may have to bedeclared at the end. An example of this is illustrated in FIG. 44, whichuses the LTE RLF as a baseline.

Referring now to FIG. 44, an example is shown from the beam recoveryperspective, and an example is shown from the link recovery perspective.In beam recovery, when serving beam quality degradation is detected(e.g., out of sync, misalignment indication), lower layers (e.g., PHYor/and MAC) of the UE may keep monitoring the serving beam (e.g.,expecting the signal quality would rebound) or/and perform correspondingbeam management procedures (e.g., refine the alignment of the servingbeams, such as adjust the precoding matrix, beamforming weights, etc.).If the serving beam(s) is/are successfully recovered within the phase 1,beam recovery process may terminate and the UE may go back to normaloperation. Otherwise, the process may report that a serving beam failureis detected, and may go to phase 2. The value of N1 may be based ontimer or other (e.g. counting) criteria. In beam recovery phase 2, in anexample, the UE evaluates and switches to other candidates beams, ifnecessary. Note that each candidate beam may have a radio quality (e.g.,SNR, RSRP, RSRQ, RSSI) that is above a preconfigured or dynamicallyconfigured absolute or relative (to the serving beam) threshold. Ifalternative beam(s) is/are successfully found and switched to be newserving beam(s), beam recovery process terminates and UE goes back tonormal operation. Otherwise, beam recovery also terminates but radiolink failure is declared, and UE enters RL recovery phase 2.

From the link recovery perspective, the failure of beam recovery phase 1may trigger the start of RL recovery phase 1. Typically, the duration ofbeam recovery phase 2 and RL recovery phase 1 are timely aligned, but itmay not be always the case. This is because the two processes may berunning in parallel. Before the termination of beam recover phase 2,link recovery phase may start evaluating other cells so that UE canperform cell reselection immediately once beam recovery phase 2 isfinished.

In summary, when a sudden serving beam quality drop is detected, in someexamples, the beam recovery process is initiated first. If beam recoveryfails even after the timer or other (e.g., counting) criteria (N1 andN2), in an example, radio link failure is declared and the second phaseof link recovery starts. The behaviors in the second phase are the sameas LTE in some cases. It is recognized herein that, in multi-beam basedNR networks, a UE may under coverage of multiple beams from the same ordifferent TRPs/cells. When there exists alternative beam(s) forcommunication, the link connection between UE and network may be quicklyrestored via beam recovery procedure, without going through the costlyRLF declarations and unnecessary RRC connection re-establishments.

Proposed beam recovery mechanisms for downlink beam management arediscussed in further detail below. In order to adapt to fastchannel/beam variances, UE initiated beam recovery actions areconsidered, where the UE behaviors (e.g., beam quality measurements,beam recovery triggers) may be configured by the network via explicitsignaling. Network initiated beam recovery is also possible (especiallyin the case of uplink based beam management).

For beam measurements, idle mode or connected mode UE may use same ordifferent synchronization signals (SS), where the periodicity of idlemode SS is assumed to be known but connected mode SS can be dependent onconfiguration. Extra reference signals, such as specific mobilityreference signals (MRS) and UE specific CIS-RS, may be available aswell.

Measurements in beam recovery process serve various purposes. An examplepurpose is to serve beam quality monitoring and evaluation. Thisprocedure may be used to detect serving beam quality degradationpromptly. For different UE use cases and service requirements, thefrequency of performing this procedure might need to be flexible andconfigurable to reach a balance between the latency and powerconsumption. This procedure may also used in the beam recovery phase 1,so that the alignment of serving beam(s) may be properly refined, e.g.adjust the precoding matrix, beamforming weights, etc. In addition, incase serving beam quality becomes good enough again (e.g., RSRP value isabove certain threshold), the beam recovery process may need to beterminated based on the measurement results of this procedure. Forexample, in some cases, moving obstacles appear and then disappear.

Another example purpose is for other candidate beams measurements andevaluation. In order to perform beam recovery, the UE may need toreplace the degraded serving beams with alternative beams with goodquality, and the measurement based evaluation of candidate beams may benecessary. This procedure may be performed in beam recovery phase 2.

In some examples, the list of candidate beams may be saved from previousmeasurements and may be statically preconfigured or dynamicallyreconfigured by the network. The list of candidate beams may be providedby PHY/MAC layer for fast access, or provided by RRC layer from onlinemeasurements or explicitly signaled by the network. If qualified beamsare identified from the measurements and evaluation process applied onthe candidate beams, regular beam switching and alignment procedures areperformed and the recovery process terminates. Otherwise, if alternativebeams are not identified or switched/aligned within a predefined timebudget (e.g., N2 in FIG. 11), beam recovery is failed and radio linkfailure is declared to trigger the start of RL recovery phase 2, whichis LTE like RLF recovery phase 2.

In one embodiment, conditions to trigger beam recovery process aredefined. For this definition, the following exemplary conditions andrelated thresholds are included. The first is trigger events and relatedthresholds: (i) Serving beam(s) misalignment detected, out-of-syncdetected; (ii) Quality of serving beam(s) below certain threshold, e.g.,RSRP, SNR, RSRQ, RSSI; (iii) Moving averaged or/and weighted averagedquality of N-best candidate beams is above or below certain threshold;(iv) Expected messages (signals or data) not received, or received withlow SNR; (v) Random access problem in MAC; and (vi) New detected beamshave quality threshold value better than the serving beam(s).

As explained above, in one embodiment, only the downlink case forNetwork configured and UE initiated beam recovery was considered. Here,the UE is configured with the triggers defined above. This configurationcan be statically preconfigured or dynamically reconfigured via RRCsignaling or/and MAC control element. For different phases shown in FIG.11, corresponding measurements can be performed as defined above tofacilitate the triggering, transitions and terminations of differentphases. There can be two phases of the beam recovery process. The firstexample phase is represented by beam recovery phase 1 as in FIG. 44.

In this first phase, lower layers (e.g., PHY or/and MAC) of UE will keepmonitoring the serving beam (e.g., expecting the signal quality wouldrebound back) or/and perform corresponding beam management procedures(e.g., refine the alignment of the serving beams, such as adjust theprecoding matrix, beamforming weights, etc.). If the serving beam(s)is/are successfully recovers within the phase 1, beam recovery processterminates and UE goes back to normal operation. Otherwise, the processreports that serving beam failure detected and goes to phase 2. Theduration of this phase 1 is governed by the value of N1, which is basedon timer or other (e.g. counting consecutive out-of-sync conditions)criteria. The information of N1 may be obtained from system information,or reconfigured by the network via explicit RRC or MAC CE signals, orpreconfigured by manufacturers or operators.

The second example phase is represented by beam recovery phase 2 in FIG.44. Here, the UE evaluates and switches to other alternative beams, ifnecessary. Each qualified alternative beam may have a radio quality(e.g., SNR, RSRP, RSRQ, RSSI) that is above a preconfigured ordynamically configured absolute or relative (to the serving beam)threshold. Note that the alternative beams may be from the same TRP ordifferent TRPs of the same cell or different cells. The beams can beidentified by cell ID or beam ID or port ID. Switching between differentalternative beams is handled at layer 1/2, and only the configuration ofthe alternative beams is possibly provided by RRC. The configuration ofthe alternative beams may be based on previous saved measurements (e.g.,PHY mobility set), may be statically preconfigured bymanufacturers/operators or dynamically reconfigured by the network viaexplicit RRC and MAC signaling (e.g., NR mobility set). When measuringalternative beams, different reference signals may be used for UEs atidle, connected or inactive mode. For idle mode UEs, SS burst/SS burstset may be used for common beam reference. In addition, cell specificCSI-RS is also possible as a measurement reference signal if there isconfigured or specific mobility reference signal (MRS)/beam referencesignal (BRS). For inactive mode UEs, UE specific CSI-RS and/orconnected-mode SS burst can be used if UE can be configured by thenetwork. Otherwise, the SS burst and/or cell specific CSI-RS are used.For connected mode UEs, connected-mode SS, UE specific CSI-RS andspecific mobility reference signal (MRS)/beam reference signal (BRS) maybe used. The transmissions of the reference signal may be on-demand ornetwork scheduled. To switch to alternative beams, DL or UL signaltransmission may be needed to do beam alignment with the network, e.g.,RACH preamble sequence, DL/UL reference signal, control channel, etc. Ifnecessary, resource allocation may also be needed, e.g., RACH resource.The RACH procedure for different states of UE may use 2-step or 4-step.The RACH resource for idle mode may be decided by SS-burst (e.g.,signaling by PBCH and/or SS burst time index). In the connected-mode,the RACH resource may decide by RRC configuration or dynamicallysignaling by DCI (i.e., NR-PDCCH).

In some examples, if a link is successfully recovered by switching tonew serving beam(s), the beam recovery process terminates and UE goesback to normal operation. Otherwise, beam recovery also terminates butthe radio link failure is declared, and UE enters RL recovery phase 2.Note that in case no alternative beams available, direct transition tosecond level link recovery process may be considered.

In another embodiment, there are two phases of the link recoveryprocess. The first phase of the link recovery process is to wait for theexecution results of the second level of beam recovery process.Typically, the duration of first phase of link recovery process and thesecond level of beam recovery process are timely aligned, but it may notbe always the case. This is because the two phase processes may berunning in parallel. Before the termination of the second phase of beamrecovery process, link recovery phase 1 may start evaluating other cellsso that UE can perform cell reselection immediately once beam recoveryphase 2 is finished.

In the second phase, in order to resume activity and avoid going viaRRC_IDLE when the UE returns to the same cell or when the UE selects adifferent cell from the same gNB, or when the UE selects a cell from adifferent gNB, the following procedure applies: (i) The UE stays inRRC_CONNECTED; (ii) The UE accesses the cell through the random accessprocedure; and (iii) The UE identifier used in the random accessprocedure for contention resolution (i.e. LTE like C RNTI of the UE inthe cell where the RLF occurred+physical layer identity of thatcell+short MAC—I based on the keys of that cell) is used by the selectedgNB to authenticate the UE and check whether it has a context stored forthat UE: (a) If the gNB finds a context that matches the identity of theUE, or obtains this context from the previously serving gNB, itindicates to the UE that its connection can be resumed; and (b) If thecontext is not found, RRC connection is released and UE initiatesprocedure to establish new RRC connection. In this case UE is requiredto go via RRC_IDLE.

In another embodiment, a demand transmission of measurement signalsduring beam recovery process is provided. When UE evaluates eitherserving beam(s) or other alternative beam(s), on-demand transmissions ofmeasurement signals for those beams may be necessary to provide accuratemeasurement results. The beams sending on-demand measurement signals maybe originally considered to be unavailable, for energy saving orinterference avoidance purposes.

The measurement signals may be requested to be sent in batch (multiplemeasurement signal transmission repeated over a certain time interval),in case UE mobility occurs more frequently and beam recovery performsfrequently.

In another embodiment, a transient from beam recovery process to linkrecovery process is described. Depending on UE use cases, states andrequested services, balance between energy efficiency and latency(data/signal transmission/reception interruption) needs to beconsidered. The time budget and behaviors (e.g., measurement gap,measurement objects) for beam recovery process needs to be adapted,e.g., timer or other (e.g. counting consecutive out-of-sync conditions)criteria (e.g., N1, N2, etc.), threshold during measurements.

Turning now to beam diversity, a UE may be configured to monitor M>=1beam pair links (BPL) between the UE and gNB(s). In an example, the BPLthat the UE will monitor the most frequently is defined as the activeBPL. Other BPLs in the monitored set may be monitored or detected with alonger duty cycle, and denoted as non-active BPL(s). These BPLs in themonitored BPL set may be transmitted by different gNB, or different TRPsbelonging to the same gNB, or the same TRP.

In some examples, the beam ID may be used with other parameters such ascell ID, slot index etc. to scramble the DM-RS sequence of NR-PDCCH forbeam diversity. One example is now described below for the purpose ofillustration; however the actual design is not limited to the example.For instance, suppose a NR-PDCCH uses k antenna ports for transmission.For any of the antenna ports p∈{n, n+1, . . . n+k−1}, thereference-signal sequence r(m) is defined by:

${{r(m)} = {{\frac{1}{\sqrt{2}}( {1 - {2 \cdot {c( {2m} )}}} )} + {j\frac{1}{\sqrt{2}}( {1 - {2 \cdot {c( {{2m} + 1} )}}} )}}},$

The pseudo-random sequence c(i) is the base sequence to build the DM-RSsequence. The sequence c(i) can be a ZAZAC sequence, M sequence, orother sequences. The pseudo-random sequence generator may be initializedwith:

c _(init)=(└n _(s)/2┘+1)·(2N _(ID) ^(cell) +f(n _(beamID))+1)·2¹⁶ +n_(RNTI), or

c _(init)=(└n _(s)/2┘+1)·(2n _(ID) ^((n) ^(SCID) ⁾ +f(n_(beamID))+1)·2¹⁶ +n _(SCID)

Depending on different cases of the monitored beam transmitter locations(e.g., same or different cells, etc.), different NR-PDCCH designs may beemployed in accordance with various embodiments. For the NR-PDCCHstransmitted using different beams or BPLs from the same or differentTRP(s) of the same cell, the contents of active and non-active NR-PDCCHsmay be the same. Those NR-PDCCHs may use corresponding DM-RS thatutilize beam ID as one of the scrambling parameters as described above.Alternatively, with respect to the NR-PDCCHs transmitted using differentbeams or BPLs from different cells, there may be different embodimentsfor NR-PDCCH contents/information. In one example, the contents ofactive and non-active NR-PDCCHs are the same. In this way, a cell thattransmits a NR-PDCCH to the UE using a non-active BPL may need toreserve the same physical channel resources as in the cell thattransmits a NR-PDCCH to the UE using the active BPL. In another example,the contents of active and non-active NR-PDCCHs are different. Forexample, considering the purpose of transmitting a NR-PDCCH is, in somecases, to increase the beam diversity, in one embodiment the NR-PDCCH istransmitted on a non-active BPL, which can be a UCI (uplink schedulinggrant or similar) carrying information including an UL resourceindication for the UE to transmit a BPL switching command/handshakingsignaling or beam reporting feedback of the non-active BPL. The UE canmonitor at least two beam-paired links (BPL) for monitoring theNR-PDCCH. In an example, one BPL is from the active BPL and the otherBPLs are from non-active BPLs. In some cases, if UE cannot decode theNR-PDCCH from the active BPL successfully, but can decode the NR-PDCCHfrom the non-active BPL successfully, then UE can use UL UCI to reportBPL switching command/handshaking signaling or beam reporting feedbackof the selected non-active BPL.

In an example, when a UE is monitoring a set of MBPLs according tohigher layer or MAC CE or physical control channel configurations, itmay detect NR-PDCCHs on one or several non-active BPLs with a lower dutycycle in addition to its regular detection of NR-PDCCH on active BPL.When the UE monitors NR-PDCCH on the active BPL and NR-PDCCH on at leastone non-active BPL in the same sub-frame or TTI, it may perform inaccordance with various rules. For example, if the UE decodes only theNR-PDCCH on the active BPL successfully, it may follow transmission orreception operation indicated in the NR-PDCCH (which can be a UCI or DCIor paging etc.). In some examples, if the UE decodes the NR-PDCCH on theactive BPL and at least one NR-PDCCH on a non-active BPL successfully,it may follow transmission or reception operations indicated in theNR-PDCCH (which can be a UCI or DCI or paging etc.) transmitted on theactive BPL, and ignore the NR-PDCCH transmitted on the non-active BPL.In an example, if the UE decodes only one NR-PDCCH on a non-active BPLsuccessfully, it may follow transmission or reception operationindicated in the NR-PDCCH (which can be a UCI or DCI or paging etc.)transmitted on the non-active BPL. In this example where the decodedNR-PDCCH is a DCI, the UE may perform data reception accordingly andfeedback ACK/NACK for received DL data with either explicit or implicitsignaling that it has switched to the non-active BPL (due to failure ofdetecting a valid NR-PDCCH on the active BPL). One example of theimplicit signaling is where the transmitting cell dynamicallyallocates/configures UL control channels resources for ACK/NACKfeedback, whose resource index has a one-to-one mapping to parameters ofNR-PDCCH that allocates the corresponding data transmission (forexample, the index of first CCE/REG of the NR-PDCCH) and the beam ID orBPL index. In some cases, if the UE decodes more than one NR-PDCCH onon-active BPLs successfully, it may follow a pre-defined tie-breakingrule to pick one NR-PDCCH to perform its transmission or receptionoperation. An example rule is one where the best SINR is selected.

Referring to FIG. 45, in an example UE-specific PDCCH, the UE sends CSIreports to the gNB (at 4506) in the connected mode after beam training,which may include beam sweeping (at 4502) and beam refining (at 4504).The CSI report at 4506 may contain the quality of multiple beams as wellas the beam ID of each reported beam. The beam ID may be indicatedexplicitly or implicitly by the symbol index and the antenna port indexor CSI-RS index. At 4508, the gNB may determine various sets of beamsbased on the current and previous CSI reports. For example, the gNB maydetermine a beam monitoring set, which may contain M beams. The UE maymonitor the quality of these beams periodically by measuring thecorresponding B-RS, M-RS, or CSI-RS. The gNB may also determine a beamcandidate set, which may contain N beams chosen from the beam monitorset, where N≤M. The gNB may select one or more beams for this set forPDCCH transmission. In some cases, the UE has to try all these beams andtheir corresponding search spaces for PDCCH blind decoding. In anexample, the IDs of the beams in the beam monitoring set may beconfigured to the UE through RRC signaling. Then the UE may monitor thequality of the beams in the beam monitoring set by measuring thecorresponding B-RS, M-RS or CSI-RS, and may feedback the CSI reportsaccordingly at 4510.

Based on the UE's CSI reports, the gNB selects N beams from the beammonitoring set, where these N beams are the candidates for the UE'sPDCCH beam diversity transmission. The gNB may select the N beams withthe best quality, e.g., the beams with the largest rank or the beamswith the highest CQI. In an example, the IDs of the N selected beams areconfigured to the UE by RRC signaling. In some cases, the gNB maydynamically choose one or more beams from the beam candidate set forPDCCH transmission, and does not need to inform the UE of the chosenbeam IDs. In some examples, however, the number of the selected beamsmay be signaled the UE by RRC signaling or common (or group) PDCCH or betransparent to the UE. When multiple beams are selected, the gNB maytransmit the same DCI through these beams to achieve the beam diversity.In an example, the DCI is scrambled with the UE's ID, which may be theUE's RNTI or other NR UE IDs, so that after blind decoding the UE mayidentify whether the DCI belongs to itself. The gNB may update the beamcandidate set based on the UE's recent CSI reports, e.g., changing somecandidate beams by beams from monitoring set with better qualities. Incase that a candidate beam is blocked, the gNB may change it with betterbeam from the monitoring set. If the gNB or the UE determines that thenumber of beams in the monitoring set have a quality better than a giventhreshold is less than a predefined number (at 4512), the process mayreturn to 4502 and 4504, where it may request or initiate a new beamsweeping and beam refining procedure to form a new beam monitoring set.Alternatively, if the number of beams that achieve a given threshold isgreater than a predefined number, the process may proceed to 4514, wherethe gNB updates the beam candidate set accordingly.

In an example, the UE-specific search space consists of time-frequency(TF) resources for every beam in the beam candidate set, and each TFresource may contain one or more PDCCH candidates. The UE-specificsearch space configuration may be based on the UE's ID and the UE'scurrent beam candidate set. As shown in FIG. 46, the TF resource may bemapped to the UE's ID and the candidate beam ID. The beam ID may beconfigured such that all the beams in the neighbor cells have differentbeam IDs. For the same UE, the TF resources for different beams may beoverlapped, and different UEs may share the same TF resources. To takeadvantage of frequency diversity, the UE-specific search spaceconfiguration may also be determined by the slot index, so that theUE-specific search space may be assigned to different subcarriers atdifferent slots.

Still referring to FIG. 46, in some cases, the UE performs blinddecoding of the PDCCH only on the PDCCH candidates in the search space.For each PDCCH candidate, the receive beam may be selected according tothe transmit beam mapped to the PDCCH candidate to reduce thecomplexity. For example, to decode the DCI in TF resource 7, the UE-1selects the receive beam according to transmit beam 10 in Cell A.

The UE-specific PDCCH may be transmitted in a subband to reduce thecomplexity of the blind decoding. The configuration of the subbandtransmission may be signaled to the UE by RRC signaling. Multiple UEsmay be configured to the same subband or overlapped subbands for PDCCHtransmission, and to take advantage of frequency diversity, a hoppingpattern may be assigned to the UE.

The 3rd Generation Partnership Project (3GPP) develops technicalstandards for cellular telecommunications network technologies,including radio access, the core transport network, and servicecapabilities—including work on codecs, security, and quality of service.Recent radio access technology (RAT) standards include WCDMA (commonlyreferred as 3G), LTE (commonly referred as 4G), and LTE-Advancedstandards. 3GPP has begun working on the standardization of nextgeneration cellular technology, called New Radio (NR), which is alsoreferred to as “5G”. 3GPP NR standards development is expected toinclude the definition of next generation radio access technology (newRAT), which is expected to include the provision of new flexible radioaccess below 6 GHz, and the provision of new ultra-mobile broadbandradio access above 6 GHz. The flexible radio access is expected toconsist of a new, non-backwards compatible radio access in new spectrumbelow 6 GHz, and it is expected to include different operating modesthat can be multiplexed together in the same spectrum to address a broadset of 3GPP NR use cases with diverging requirements. The ultra-mobilebroadband is expected to include cmWave and mmWave spectrum that willprovide the opportunity for ultra-mobile broadband access for, e.g.,indoor applications and hotspots. In particular, the ultra-mobilebroadband is expected to share a common design framework with theflexible radio access below 6 GHz, with cmWave and mmWave specificdesign optimizations.

3GPP has identified a variety of use cases that NR is expected tosupport, resulting in a wide variety of user experience requirements fordata rate, latency, and mobility. The use cases include the followinggeneral categories: enhanced mobile broadband (e.g., broadband access indense areas, indoor ultra-high broadband access, broadband access in acrowd, 50+ Mbps everywhere, ultra-low cost broadband access, mobilebroadband in vehicles), critical communications, massive machine typecommunications, network operation (e.g., network slicing, routing,migration and interworking, energy savings), and enhancedvehicle-to-everything (eV2X) communications. Specific service andapplications in these categories include, e.g., monitoring and sensornetworks, device remote controlling, bi-directional remote controlling,personal cloud computing, video streaming, wireless cloud-based office,first responder connectivity, automotive ecall, disaster alerts,real-time gaming, multi-person video calls, autonomous driving,augmented reality, tactile internet, and virtual reality to name a few.All of these use cases and others are contemplated herein.

FIG. 47A illustrates one embodiment of an example communications system100 in which the methods and apparatuses described and claimed hereinmay be embodied. As shown, the example communications system 100 mayinclude wireless transmit/receive units (WTRUs) 102 a, 102 b, 102 c,and/or 102 d (which generally or collectively may be referred to as WTRU102), a radio access network (RAN) 103/104/105/103 b/104 b/105 b, a corenetwork 106/107/109, a public switched telephone network (PSTN) 108, theInternet 110, and other networks 112, though it will be appreciated thatthe disclosed embodiments contemplate any number of WTRUs, basestations, networks, and/or network elements. Each of the WTRUs 102 a,102 b, 102 c, 102 d, 102 e may be any type of apparatus or deviceconfigured to operate and/or communicate in a wireless environment.Although each WTRU 102 a, 102 b, 102 c, 102 d, 102 e is depicted inFIGS. 47A-47E as a hand-held wireless communications apparatus, it isunderstood that with the wide variety of use cases contemplated for 5Gwireless communications, each WTRU may comprise or be embodied in anytype of apparatus or device configured to transmit and/or receivewireless signals, including, by way of example only, user equipment(UE), a mobile station, a fixed or mobile subscriber unit, a pager, acellular telephone, a personal digital assistant (PDA), a smartphone, alaptop, a tablet, a netbook, a notebook computer, a personal computer, awireless sensor, consumer electronics, a wearable device such as a smartwatch or smart clothing, a medical or eHealth device, a robot,industrial equipment, a drone, a vehicle such as a car, truck, train, orairplane, and the like.

The communications system 100 may also include a base station 114 a anda base station 114 b. Base stations 114 a may be any type of deviceconfigured to wirelessly interface with at least one of the WTRUs 102 a,102 b, 102 c to facilitate access to one or more communication networks,such as the core network 106/107/109, the Internet 110, and/or the othernetworks 112. Base stations 114 b may be any type of device configuredto wiredly and/or wirelessly interface with at least one of the RRHs(Remote Radio Heads) 118 a, 118 b and/or TRPs (Transmission andReception Points) 119 a, 119 b to facilitate access to one or morecommunication networks, such as the core network 106/107/109, theInternet 110, and/or the other networks 112. RRHs 118 a, 118 b may beany type of device configured to wirelessly interface with at least oneof the WTRU 102 c, to facilitate access to one or more communicationnetworks, such as the core network 106/107/109, the Internet 110, and/orthe other networks 112. TRPs 119 a, 119 b may be any type of deviceconfigured to wirelessly interface with at least one of the WTRU 102 d,to facilitate access to one or more communication networks, such as thecore network 106/107/109, the Internet 110, and/or the other networks112. By way of example, the base stations 114 a, 114 b may be a basetransceiver station (BTS), a Node-B, an eNode B, a Home Node B, a HomeeNode B, a site controller, an access point (AP), a wireless router, andthe like. While the base stations 114 a, 114 b are each depicted as asingle element, it will be appreciated that the base stations 114 a, 114b may include any number of interconnected base stations and/or networkelements.

The base station 114 a may be part of the RAN 103/104/105, which mayalso include other base stations and/or network elements (not shown),such as a base station controller (BSC), a radio network controller(RNC), relay nodes, etc. The base station 114 b may be part of the RAN103 b/104 b/105 b, which may also include other base stations and/ornetwork elements (not shown), such as a base station controller (BSC), aradio network controller (RNC), relay nodes, etc. The base station 114 amay be configured to transmit and/or receive wireless signals within aparticular geographic region, which may be referred to as a cell (notshown). The base station 114 b may be configured to transmit and/orreceive wired and/or wireless signals within a particular geographicregion, which may be referred to as a cell (not shown). The cell mayfurther be divided into cell sectors. For example, the cell associatedwith the base station 114 a may be divided into three sectors. Thus, inan embodiment, the base station 114 a may include three transceivers,e.g., one for each sector of the cell. In an embodiment, the basestation 114 a may employ multiple-input multiple output (MIMO)technology and, therefore, may utilize multiple transceivers for eachsector of the cell.

The base stations 114 a may communicate with one or more of the WTRUs102 a, 102 b, 102 c over an air interface 115/116/117, which may be anysuitable wireless communication link (e.g., radio frequency (RF),microwave, infrared (IR), ultraviolet (UV), visible light, cmWave,mmWave, etc.). The air interface 115/116/117 may be established usingany suitable radio access technology (RAT).

The base stations 114 b may communicate with one or more of the RRHs 118a, 118 b and/or TRPs 119 a, 119 b over a wired or air interface 115b/116 b/117 b, which may be any suitable wired (e.g., cable, opticalfiber, etc.) or wireless communication link (e.g., radio frequency (RF),microwave, infrared (IR), ultraviolet (UV), visible light, cmWave,mmWave, etc.). The air interface 115 b/116 b/117 b may be establishedusing any suitable radio access technology (RAT).

The RRHs 118 a, 118 b and/or TRPs 119 a, 119 b may communicate with oneor more of the WTRUs 102 c, 102 d over an air interface 115 c/116 c/117c, which may be any suitable wireless communication link (e.g., radiofrequency (RF), microwave, infrared (IR), ultraviolet (UV), visiblelight, cmWave, mmWave, etc.). The air interface 115 c/116 c/117 c may beestablished using any suitable radio access technology (RAT).

More specifically, as noted above, the communications system 100 may bea multiple access system and may employ one or more channel accessschemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. Forexample, the base station 114 a in the RAN 103/104/105 and the WTRUs 102a, 102 b, 102 c, or RRHs 118 a, 118 b and TRPs 119 a, 119 b in the RAN103 b/104 b/105 b and the WTRUs 102 c, 102 d, may implement a radiotechnology such as Universal Mobile Telecommunications System (UMTS)Terrestrial Radio Access (UTRA), which may establish the air interface115/116/117 or 115 c/116 c/117 c respectively using wideband CDMA(WCDMA). WCDMA may include communication protocols such as High-SpeedPacket Access (HSPA) and/or Evolved HSPA (HSPA+). HSPA may includeHigh-Speed Downlink Packet Access (HSDPA) and/or High-Speed UplinkPacket Access (HSUPA).

In an embodiment, the base station 114 a and the WTRUs 102 a, 102 b, 102c, or RRHs 118 a, 118 b and TRPs 119 a, 119 b in the RAN 103 b/104 b/105b and the WTRUs 102 c, 102 d, may implement a radio technology such asEvolved UMTS Terrestrial Radio Access (E-UTRA), which may establish theair interface 115/116/117 or 115 c/116 c/117 c respectively using LongTerm Evolution (LTE) and/or LTE-Advanced (LTE-A). In the future, the airinterface 115/116/117 may implement 3GPP NR technology.

In an embodiment, the base station 114 a in the RAN 103/104/105 and theWTRUs 102 a, 102 b, 102 c, or RRHs 118 a, 118 b and TRPs 119 a, 119 b inthe RAN 103 b/104 b/105 b and the WTRUs 102 c, 102 d, may implementradio technologies such as IEEE 802.16 (e.g., Worldwide Interoperabilityfor Microwave Access (WiMAX)), CDMA2000, CDMA2000 1×, CDMA2000 EV-DO,Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), InterimStandard 856 (IS-856), Global System for Mobile communications (GSM),Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and thelike.

The base station 114 c in FIG. 47A may be a wireless router, Home NodeB, Home eNode B, or access point, for example, and may utilize anysuitable RAT for facilitating wireless connectivity in a localized area,such as a place of business, a home, a vehicle, a campus, and the like.In an embodiment, the base station 114 c and the WTRUs 102 e, mayimplement a radio technology such as IEEE 802.11 to establish a wirelesslocal area network (WLAN). In an embodiment, the base station 114 c andthe WTRUs 102 d, may implement a radio technology such as IEEE 802.15 toestablish a wireless personal area network (WPAN). In yet an embodiment,the base station 114 c and the WTRUs 102 e, may utilize a cellular-basedRAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, etc.) to establish apicocell or femtocell. As shown in FIG. 47A, the base station 114 b mayhave a direct connection to the Internet 110. Thus, the base station 114c may not be required to access the Internet 110 via the core network106/107/109.

The RAN 103/104/105 and/or RAN 103 b/104 b/105 b may be in communicationwith the core network 106/107/109, which may be any type of networkconfigured to provide voice, data, applications, and/or voice overinternet protocol (VoIP) services to one or more of the WTRUs 102 a, 102b, 102 c, 102 d. For example, the core network 106/107/109 may providecall control, billing services, mobile location-based services, pre-paidcalling, Internet connectivity, video distribution, etc., and/or performhigh-level security functions, such as user authentication.

Although not shown in FIG. 47A, it will be appreciated that the RAN103/104/105 and/or RAN 103 b/104 b/105 b and/or the core network106/107/109 may be in direct or indirect communication with other RANsthat employ the same RAT as the RAN 103/104/105 and/or RAN 103 b/104b/105 b or a different RAT. For example, in addition to being connectedto the RAN 103/104/105 and/or RAN 103 b/104 b/105 b, which may beutilizing an E-UTRA radio technology, the core network 106/107/109 mayalso be in communication with another RAN (not shown) employing a GSMradio technology.

The core network 106/107/109 may also serve as a gateway for the WTRUs102 a, 102 b, 102 c, 102 d, 102 e to access the PSTN 108, the Internet110, and/or other networks 112. The PSTN 108 may includecircuit-switched telephone networks that provide plain old telephoneservice (POTS). The Internet 110 may include a global system ofinterconnected computer networks and devices that use commoncommunication protocols, such as the transmission control protocol(TCP), user datagram protocol (UDP) and the internet protocol (IP) inthe TCP/IP internet protocol suite. The networks 112 may include wiredor wireless communications networks owned and/or operated by otherservice providers. For example, the networks 112 may include anothercore network connected to one or more RANs, which may employ the sameRAT as the RAN 103/104/105 and/or RAN 103 b/104 b/105 b or a differentRAT.

Some or all of the WTRUs 102 a, 102 b, 102 c, 102 d in thecommunications system 100 may include multi-mode capabilities, e.g., theWTRUs 102 a, 102 b, 102 c, 102 d, and 102 e may include multipletransceivers for communicating with different wireless networks overdifferent wireless links. For example, the WTRU 102 e shown in FIG. 47Amay be configured to communicate with the base station 114 a, which mayemploy a cellular-based radio technology, and with the base station 114c, which may employ an IEEE 802 radio technology.

FIG. 47B is a block diagram of an example apparatus or device configuredfor wireless communications in accordance with the embodimentsillustrated herein, such as for example, a WTRU 102. As shown in FIG.47B, the example WTRU 102 may include a processor 118, a transceiver120, a transmit/receive element 122, a speaker/microphone 124, a keypad126, a display/touchpad/indicators 128, non-removable memory 130,removable memory 132, a power source 134, a global positioning system(GPS) chipset 136, and other peripherals 138. It will be appreciatedthat the WTRU 102 may include any sub-combination of the foregoingelements while remaining consistent with an embodiment. Also,embodiments contemplate that the base stations 114 a and 114 b, and/orthe nodes that base stations 114 a and 114 b may represent, such as butnot limited to transceiver station (BTS), a Node-B, a site controller,an access point (AP), a home node-B, an evolved home node-B (eNodeB), ahome evolved node-B (HeNB), a home evolved node-B gateway, and proxynodes, among others, may include some or all of the elements depicted inFIG. 47B and described herein.

The processor 118 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Array (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 118 may perform signal coding, dataprocessing, power control, input/output processing, and/or any otherfunctionality that enables the WTRU 102 to operate in a wirelessenvironment. The processor 118 may be coupled to the transceiver 120,which may be coupled to the transmit/receive element 122. While FIG. 47Bdepicts the processor 118 and the transceiver 120 as separatecomponents, it will be appreciated that the processor 118 and thetransceiver 120 may be integrated together in an electronic package orchip.

The transmit/receive element 122 may be configured to transmit signalsto, or receive signals from, a base station (e.g., the base station 114a) over the air interface 115/116/117. For example, in an embodiment,the transmit/receive element 122 may be an antenna configured totransmit and/or receive RF signals. In an embodiment, thetransmit/receive Although not shown in FIG. 47A, it will be appreciatedthat the RAN 103/104/105 and/or the core network 106/107/109 may be indirect or indirect communication with other RANs that employ the sameRAT as the RAN 103/104/105 or a different RAT. For example, in additionto being connected to the RAN 103/104/105, which may be utilizing anE-UTRA radio technology, the core network 106/107/109 may also be incommunication with another RAN (not shown) employing a GSM radiotechnology.

The core network 106/107/109 may also serve as a gateway for the WTRUs102 a, 102 b, 102 c, 102 d to access the PSTN 108, the Internet 110,and/or other networks 112. The PSTN 108 may include circuit-switchedtelephone networks that provide plain old telephone service (POTS). TheInternet 110 may include a global system of interconnected computernetworks and devices that use common communication protocols, such asthe transmission control protocol (TCP), user datagram protocol (UDP)and the internet protocol (IP) in the TCP/IP internet protocol suite.The networks 112 may include wired or wireless communications networksowned and/or operated by other service providers. For example, thenetworks 112 may include another core network connected to one or moreRANs, which may employ the same RAT as the RAN 103/104/105 or adifferent RAT.

Some or all of the WTRUs 102 a, 102 b, 102 c, 102 d in thecommunications system 100 may include multi-mode capabilities, e.g., theWTRUs 102 a, 102 b, 102 c, and 102 d may include multiple transceiversfor communicating with different wireless networks over differentwireless links. For example, the WTRU 102 c shown in FIG. 47A may beconfigured to communicate with the base station 114 a, which may employa cellular-based radio technology, and with the base station 114 b,which may employ an IEEE 802 radio technology.

FIG. 47B is a block diagram of an example apparatus or device configuredfor wireless communications in accordance with the embodimentsillustrated herein, such as for example, a WTRU 102. As shown in FIG.47B, the example WTRU 102 may include a processor 118, a transceiver120, a transmit/receive element 122, a speaker/microphone 124, a keypad126, a display/touchpad/indicators 128, non-removable memory 130,removable memory 132, a power source 134, a global positioning system(GPS) chipset 136, and other peripherals 138. It will be appreciatedthat the WTRU 102 may include any sub-combination of the foregoingelements while remaining consistent with an embodiment. Also,embodiments contemplate that the base stations 114 a and 114 b, and/orthe nodes that base stations 114 a and 114 b may represent, such as butnot limited to transceiver station (BTS), a Node-B, a site controller,an access point (AP), a home node-B, an evolved home node-B (eNodeB), ahome evolved node-B (HeNB), a home evolved node-B gateway, and proxynodes, among others, may include some or all of the elements depicted inFIG. 47B and described herein.

The processor 118 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Array (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 118 may perform signal coding, dataprocessing, power control, input/output processing, and/or any otherfunctionality that enables the WTRU 102 to operate in a wirelessenvironment. The processor 118 may be coupled to the transceiver 120,which may be coupled to the transmit/receive element 122. While FIG. 47Bdepicts the processor 118 and the transceiver 120 as separatecomponents, it will be appreciated that the processor 118 and thetransceiver 120 may be integrated together in an electronic package orchip.

The transmit/receive element 122 may be configured to transmit signalsto, or receive signals from, a base station (e.g., the base station 114a) over the air interface 115/116/117. For example, in an embodiment,the transmit/receive element 122 may be an antenna configured totransmit and/or receive RF signals. In an embodiment, thetransmit/receive element 122 may be an emitter/detector configured totransmit and/or receive IR, UV, or visible light signals, for example.In yet an embodiment, the transmit/receive element 122 may be configuredto transmit and receive both RF and light signals. It will beappreciated that the transmit/receive element 122 may be configured totransmit and/or receive any combination of wireless signals.

In addition, although the transmit/receive element 122 is depicted inFIG. 47B as a single element, the WTRU 102 may include any number oftransmit/receive elements 122. More specifically, the WTRU 102 mayemploy MIMO technology. Thus, in an embodiment, the WTRU 102 may includetwo or more transmit/receive elements 122 (e.g., multiple antennas) fortransmitting and receiving wireless signals over the air interface115/116/117.

The transceiver 120 may be configured to modulate the signals that areto be transmitted by the transmit/receive element 122 and to demodulatethe signals that are received by the transmit/receive element 122. Asnoted above, the WTRU 102 may have multi-mode capabilities. Thus, thetransceiver 120 may include multiple transceivers for enabling the WTRU102 to communicate via multiple RATs, such as UTRA and IEEE 802.11, forexample.

The processor 118 of the WTRU 102 may be coupled to, and may receiveuser input data from, the speaker/microphone 124, the keypad 126, and/orthe display/touchpad/indicators 128 (e.g., a liquid crystal display(LCD) display unit or organic light-emitting diode (OLED) display unit).The processor 118 may also output user data to the speaker/microphone124, the keypad 126, and/or the display/touchpad/indicators 128. Inaddition, the processor 118 may access information from, and store datain, any type of suitable memory, such as the non-removable memory 130and/or the removable memory 132. The non-removable memory 130 mayinclude random-access memory (RAM), read-only memory (ROM), a hard disk,or any other type of memory storage device. The removable memory 132 mayinclude a subscriber identity module (SIM) card, a memory stick, asecure digital (SD) memory card, and the like. In an embodiment, theprocessor 118 may access information from, and store data in, memorythat is not physically located on the WTRU 102, such as on a server or ahome computer (not shown).

The processor 118 may receive power from the power source 134, and maybe configured to distribute and/or control the power to the othercomponents in the WTRU 102. The power source 134 may be any suitabledevice for powering the WTRU 102. For example, the power source 134 mayinclude one or more dry cell batteries, solar cells, fuel cells, and thelike.

The processor 118 may also be coupled to the GPS chipset 136, which maybe configured to provide location information (e.g., longitude andlatitude) regarding the current location of the WTRU 102. In additionto, or in lieu of, the information from the GPS chipset 136, the WTRU102 may receive location information over the air interface 115/116/117from a base station (e.g., base stations 114 a, 114 b) and/or determineits location based on the timing of the signals being received from twoor more nearby base stations. It will be appreciated that the WTRU 102may acquire location information by way of any suitablelocation-determination method while remaining consistent with anembodiment.

The processor 118 may further be coupled to other peripherals 138, whichmay include one or more software and/or hardware modules that provideadditional features, functionality and/or wired or wirelessconnectivity. For example, the peripherals 138 may include varioussensors such as an accelerometer, biometrics (e.g., finger print)sensors, an e-compass, a satellite transceiver, a digital camera (forphotographs or video), a universal serial bus (USB) port or otherinterconnect interfaces, a vibration device, a television transceiver, ahands free headset, a Bluetooth® module, a frequency modulated (FM)radio unit, a digital music player, a media player, a video game playermodule, an Internet browser, and the like.

The WTRU 102 may be embodied in other apparatuses or devices, such as asensor, consumer electronics, a wearable device such as a smart watch orsmart clothing, a medical or eHealth device, a robot, industrialequipment, a drone, a vehicle such as a car, truck, train, or airplane.The WTRU 102 may connect to other components, modules, or systems ofsuch apparatuses or devices via one or more interconnect interfaces,such as an interconnect interface that may comprise one of theperipherals 138.

FIG. 47C is a system diagram of the RAN 103 and the core network 106according to an embodiment. As noted above, the RAN 103 may employ aUTRA radio technology to communicate with the WTRUs 102 a, 102 b, and102 c over the air interface 115. The RAN 103 may also be incommunication with the core network 106. As shown in FIG. 47C, the RAN103 may include Node-Bs 140 a, 140 b, 140 c, which may each include oneor more transceivers for communicating with the WTRUs 102 a, 102 b, 102c over the air interface 115. The Node-Bs 140 a, 140 b, 140 c may eachbe associated with a particular cell (not shown) within the RAN 103. TheRAN 103 may also include RNCs 142 a, 142 b. It will be appreciated thatthe RAN 103 may include any number of Node-Bs and RNCs while remainingconsistent with an embodiment.

As shown in FIG. 47C, the Node-Bs 140 a, 140 b may be in communicationwith the RNC 142 a. Additionally, the Node-B 140 c may be incommunication with the RNC 142 b. The Node-Bs 140 a, 140 b, 140 c maycommunicate with the respective RNCs 142 a, 142 b via an Iub interface.The RNCs 142 a, 142 b may be in communication with one another via anIur interface. Each of the RNCs 142 a, 142 b may be configured tocontrol the respective Node-Bs 140 a, 140 b, 140 c to which it isconnected. In addition, each of the RNCs 142 a, 142 b may be configuredto carry out or support other functionality, such as outer loop powercontrol, load control, admission control, packet scheduling, handovercontrol, macro-diversity, security functions, data encryption, and thelike.

The core network 106 shown in FIG. 47C may include a media gateway (MGW)144, a mobile switching center (MSC) 146, a serving GPRS support node(SGSN) 148, and/or a gateway GPRS support node (GGSN) 150. While each ofthe foregoing elements are depicted as part of the core network 106, itwill be appreciated that any one of these elements may be owned and/oroperated by an entity other than the core network operator.

The RNC 142 a in the RAN 103 may be connected to the MSC 146 in the corenetwork 106 via an IuCS interface. The MSC 146 may be connected to theMGW 144. The MSC 146 and the MGW 144 may provide the WTRUs 102 a, 102 b,102 c with access to circuit-switched networks, such as the PSTN 108, tofacilitate communications between the WTRUs 102 a, 102 b, 102 c andtraditional land-line communications devices.

The RNC 142 a in the RAN 103 may also be connected to the SGSN 148 inthe core network 106 via an IuPS interface. The SGSN 148 may beconnected to the GGSN 150. The SGSN 148 and the GGSN 150 may provide theWTRUs 102 a, 102 b, 102 c with access to packet-switched networks, suchas the Internet 110, to facilitate communications between and the WTRUs102 a, 102 b, 102 c and IP-enabled devices.

As noted above, the core network 106 may also be connected to thenetworks 112, which may include other wired or wireless networks thatare owned and/or operated by other service providers.

FIG. 47D is a system diagram of the RAN 104 and the core network 107according to an embodiment. As noted above, the RAN 104 may employ anE-UTRA radio technology to communicate with the WTRUs 102 a, 102 b, and102 c over the air interface 116. The RAN 104 may also be incommunication with the core network 107.

The RAN 104 may include eNode-Bs 160 a, 160 b, 160 c, though it will beappreciated that the RAN 104 may include any number of eNode-Bs whileremaining consistent with an embodiment. The eNode-Bs 160 a, 160 b, 160c may each include one or more transceivers for communicating with theWTRUs 102 a, 102 b, 102 c over the air interface 116. In an embodiment,the eNode-Bs 160 a, 160 b, 160 c may implement MIMO technology. Thus,the eNode-B 160 a, for example, may use multiple antennas to transmitwireless signals to, and receive wireless signals from, the WTRU 102 a.

Each of the eNode-Bs 160 a, 160 b, and 160 c may be associated with aparticular cell (not shown) and may be configured to handle radioresource management decisions, handover decisions, scheduling of usersin the uplink and/or downlink, and the like. As shown in FIG. 47D, theeNode-Bs 160 a, 160 b, 160 c may communicate with one another over an X2interface.

The core network 107 shown in FIG. 47D may include a mobility managementgateway (MME) 162, a serving gateway 164, and a packet data network(PDN) gateway 166. While each of the foregoing elements are depicted aspart of the core network 107, it will be appreciated that any one ofthese elements may be owned and/or operated by an entity other than thecore network operator.

The MME 162 may be connected to each of the eNode-Bs 160 a, 160 b, and160 c in the RAN 104 via an S1 interface and may serve as a controlnode. For example, the MME 162 may be responsible for authenticatingusers of the WTRUs 102 a, 102 b, 102 c, bearer activation/deactivation,selecting a particular serving gateway during an initial attach of theWTRUs 102 a, 102 b, 102 c, and the like. The MME 162 may also provide acontrol plane function for switching between the RAN 104 and other RANs(not shown) that employ other radio technologies, such as GSM or WCDMA.

The serving gateway 164 may be connected to each of the eNode-Bs 160 a,160 b, and 160 c in the RAN 104 via the S1 interface. The servinggateway 164 may generally route and forward user data packets to/fromthe WTRUs 102 a, 102 b, 102 c. The serving gateway 164 may also performother functions, such as anchoring user planes during inter-eNode Bhandovers, triggering paging when downlink data is available for theWTRUs 102 a, 102 b, 102 c, managing and storing contexts of the WTRUs102 a, 102 b, 102 c, and the like.

The serving gateway 164 may also be connected to the PDN gateway 166,which may provide the WTRUs 102 a, 102 b, 102 c with access topacket-switched networks, such as the Internet 110, to facilitatecommunications between the WTRUs 102 a, 102 b, 102 c and IP-enableddevices.

The core network 107 may facilitate communications with other networks.For example, the core network 107 may provide the WTRUs 102 a, 102 b,102 c with access to circuit-switched networks, such as the PSTN 108, tofacilitate communications between the WTRUs 102 a, 102 b, 102 c andtraditional land-line communications devices. For example, the corenetwork 107 may include, or may communicate with, an IP gateway (e.g.,an IP multimedia subsystem (IMS) server) that serves as an interfacebetween the core network 107 and the PSTN 108. In addition, the corenetwork 107 may provide the WTRUs 102 a, 102 b, 102 c with access to thenetworks 112, which may include other wired or wireless networks thatare owned and/or operated by other service providers.

FIG. 47E is a system diagram of the RAN 105 and the core network 109according to an embodiment. The RAN 105 may be an access service network(ASN) that employs IEEE 802.16 radio technology to communicate with theWTRUs 102 a, 102 b, and 102 c over the air interface 117. As will befurther discussed below, the communication links between the differentfunctional entities of the WTRUs 102 a, 102 b, 102 c, the RAN 105, andthe core network 109 may be defined as reference points.

As shown in FIG. 47E, the RAN 105 may include base stations 180 a, 180b, 180 c, and an ASN gateway 182, though it will be appreciated that theRAN 105 may include any number of base stations and ASN gateways whileremaining consistent with an embodiment. The base stations 180 a, 180 b,180 c may each be associated with a particular cell in the RAN 105 andmay include one or more transceivers for communicating with the WTRUs102 a, 102 b, 102 c over the air interface 117. In an embodiment, thebase stations 180 a, 180 b, 180 c may implement MIMO technology. Thus,the base station 180 a, for example, may use multiple antennas totransmit wireless signals to, and receive wireless signals from, theWTRU 102 a. The base stations 180 a, 180 b, 180 c may also providemobility management functions, such as handoff triggering, tunnelestablishment, radio resource management, traffic classification,quality of service (QoS) policy enforcement, and the like. The ASNgateway 182 may serve as a traffic aggregation point and may beresponsible for paging, caching of subscriber profiles, routing to thecore network 109, and the like.

The air interface 117 between the WTRUs 102 a, 102 b, 102 c and the RAN105 may be defined as an R1 reference point that implements the IEEE802.16 specification. In addition, each of the WTRUs 102 a, 102 b, and102 c may establish a logical interface (not shown) with the corenetwork 109. The logical interface between the WTRUs 102 a, 102 b, 102 cand the core network 109 may be defined as an R2 reference point, whichmay be used for authentication, authorization, IP host configurationmanagement, and/or mobility management.

The communication link between each of the base stations 180 a, 180 b,and 180 c may be defined as an R8 reference point that includesprotocols for facilitating WTRU handovers and the transfer of databetween base stations. The communication link between the base stations180 a, 180 b, 180 c and the ASN gateway 182 may be defined as an R6reference point. The R6 reference point may include protocols forfacilitating mobility management based on mobility events associatedwith each of the WTRUs 102 a, 102 b, 102 c.

As shown in FIG. 47E, the RAN 105 may be connected to the core network109. The communication link between the RAN 105 and the core network 109may defined as an R3 reference point that includes protocols forfacilitating data transfer and mobility management capabilities, forexample. The core network 109 may include a mobile IP home agent(MIP-HA) 184, an authentication, authorization, accounting (AAA) server186, and a gateway 188. While each of the foregoing elements aredepicted as part of the core network 109, it will be appreciated thatany one of these elements may be owned and/or operated by an entityother than the core network operator.

The MIP-HA may be responsible for IP address management, and may enablethe WTRUs 102 a, 102 b, and 102 c to roam between different ASNs and/ordifferent core networks. The MIP-HA 184 may provide the WTRUs 102 a, 102b, 102 c with access to packet-switched networks, such as the Internet110, to facilitate communications between the WTRUs 102 a, 102 b, 102 cand IP-enabled devices. The AAA server 186 may be responsible for userauthentication and for supporting user services. The gateway 188 mayfacilitate interworking with other networks. For example, the gateway188 may provide the WTRUs 102 a, 102 b, 102 c with access tocircuit-switched networks, such as the PSTN 108, to facilitatecommunications between the WTRUs 102 a, 102 b, 102 c and traditionalland-line communications devices. In addition, the gateway 188 mayprovide the WTRUs 102 a, 102 b, 102 c with access to the networks 112,which may include other wired or wireless networks that are owned and/oroperated by other service providers.

Although not shown in FIG. 47E, it will be appreciated that the RAN 105may be connected to other ASNs and the core network 109 may be connectedto other core networks. The communication link between the RAN 105 theother ASNs may be defined as an R4 reference point, which may includeprotocols for coordinating the mobility of the WTRUs 102 a, 102 b, 102 cbetween the RAN 105 and the other ASNs. The communication link betweenthe core network 109 and the other core networks may be defined as an R5reference, which may include protocols for facilitating interworkingbetween home core networks and visited core networks.

The core network entities described herein and illustrated in FIGS. 47A,47C, 47D, and 47E are identified by the names given to those entities incertain existing 3GPP specifications, but it is understood that in thefuture those entities and functionalities may be identified by othernames and certain entities or functions may be combined in futurespecifications published by 3GPP, including future 3GPP NRspecifications. Thus, the particular network entities andfunctionalities described and illustrated in FIGS. 47A, 47B, 47C, 47D,and 47E are provided by way of example only, and it is understood thatthe subject matter disclosed and claimed herein may be embodied orimplemented in any similar communication system, whether presentlydefined or defined in the future.

FIG. 47F is a block diagram of an exemplary computing system 90 in whichone or more apparatuses of the communications networks illustrated inFIGS. 47A, 47C, 47D and 47E may be embodied, such as certain nodes orfunctional entities in the RAN 103/104/105, Core Network 106/107/109,PSTN 108, Internet 110, or Other Networks 112. Computing system 90 maycomprise a computer or server and may be controlled primarily bycomputer readable instructions, which may be in the form of software,wherever, or by whatever means such software is stored or accessed. Suchcomputer readable instructions may be executed within a processor 91, tocause computing system 90 to do work. The processor 91 may be a generalpurpose processor, a special purpose processor, a conventionalprocessor, a digital signal processor (DSP), a plurality ofmicroprocessors, one or more microprocessors in association with a DSPcore, a controller, a microcontroller, Application Specific IntegratedCircuits (ASICs), Field Programmable Gate Array (FPGAs) circuits, anyother type of integrated circuit (IC), a state machine, and the like.The processor 91 may perform signal coding, data processing, powercontrol, input/output processing, and/or any other functionality thatenables the computing system 90 to operate in a communications network.Coprocessor 81 is an optional processor, distinct from main processor91, that may perform additional functions or assist processor 91.Processor 91 and/or coprocessor 81 may receive, generate, and processdata related to the methods and apparatuses disclosed herein.

In operation, processor 91 fetches, decodes, and executes instructions,and transfers information to and from other resources via the computingsystem's main data-transfer path, system bus 80. Such a system busconnects the components in computing system 90 and defines the mediumfor data exchange. System bus 80 typically includes data lines forsending data, address lines for sending addresses, and control lines forsending interrupts and for operating the system bus. An example of sucha system bus 80 is the PCI (Peripheral Component Interconnect) bus.

Memories coupled to system bus 80 include random access memory (RAM) 82and read only memory (ROM) 93. Such memories include circuitry thatallows information to be stored and retrieved. ROMs 93 generally containstored data that cannot easily be modified. Data stored in RAM 82 can beread or changed by processor 91 or other hardware devices. Access to RAM82 and/or ROM 93 may be controlled by memory controller 92. Memorycontroller 92 may provide an address translation function thattranslates virtual addresses into physical addresses as instructions areexecuted. Memory controller 92 may also provide a memory protectionfunction that isolates processes within the system and isolates systemprocesses from user processes. Thus, a program running in a first modecan access only memory mapped by its own process virtual address space;it cannot access memory within another process's virtual address spaceunless memory sharing between the processes has been set up.

In addition, computing system 90 may contain peripherals controller 83responsible for communicating instructions from processor 91 toperipherals, such as printer 94, keyboard 84, mouse 95, and disk drive85.

Display 86, which is controlled by display controller 96, is used todisplay visual output generated by computing system 90. Such visualoutput may include text, graphics, animated graphics, and video. Thevisual output may be provided in the form of a graphical user interface(GUI). Display 86 may be implemented with a CRT-based video display, anLCD-based flat-panel display, gas plasma-based flat-panel display, or atouch-panel. Display controller 96 includes electronic componentsrequired to generate a video signal that is sent to display 86.

Further, computing system 90 may contain communication circuitry, suchas for example a network adapter 97, that may be used to connectcomputing system 90 to an external communications network, such as theRAN 103/104/105, Core Network 106/107/109, PSTN 108, Internet 110, orOther Networks 112 of FIGS. 47A, 47B, 47C, 47D, and 47E, to enable thecomputing system 90 to communicate with other nodes or functionalentities of those networks. The communication circuitry, alone or incombination with the processor 91, may be used to perform thetransmitting and receiving steps of certain apparatuses, nodes, orfunctional entities described herein.

It is understood that any or all of the apparatuses, systems, methodsand processes described herein may be embodied in the form of computerexecutable instructions (e.g., program code) stored on acomputer-readable storage medium which instructions, when executed by aprocessor, such as processors 118 or 91, cause the processor to performand/or implement the systems, methods and processes described herein.Specifically, any of the steps, operations or functions described hereinmay be implemented in the form of such computer executable instructions,executing on the processor of an apparatus or computing systemconfigured for wireless and/or wired network communications. Computerreadable storage media include volatile and nonvolatile, removable andnon-removable media implemented in any non-transitory (e.g., tangible orphysical) method or technology for storage of information, but suchcomputer readable storage media do not includes signals. Computerreadable storage media include, but are not limited to, RAM, ROM,EEPROM, flash memory or other memory technology, CD-ROM, digitalversatile disks (DVD) or other optical disk storage, magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devices,or any other tangible or physical medium which can be used to store thedesired information and which can be accessed by a computing system.

The following is a list of acronyms relating to NR technologies that mayappear in the above description. Unless otherwise specified, theacronyms used herein refer to the corresponding term listed below.

AR Augmented Reality

AS Access Stratum

BF-RS BeamForm Reference Signal

BT-RS Beamformed Training Reference Signal

CE Control Element

CoMP Coordinated Multipoint

CP Cyclic Prefix

CQI Channel Quality Indication

CRS Cell-specific Reference Signals

CSI Channel State Information

CSI-RS Channel State Information Reference Signals

DCI Downlink Control Information

DL DownLink

DM-RS Demodulation Reference Signals

eMBB enhanced Mobile Broadband

eNB evolved Node B

ePDCCH Enhanced Physical Downlink Control CHannel

FD Full-Dimension

FDD Frequency Division Duplex

FFS For Further Study

GUI Graphical User Interface

HARQ Hybrid Automatic Repeat Request

ID Identification

IMT International Mobile Telecommunications

KP Kronecker-Product

KPI Key Performance Indicators

LTE Long Term Evolution

MAC Medium Access Control

MCL Maximum Coupling Loss

MCS Modulation and Coding Scheme

MME Mobility Management Entity

MIMO Multiple-Input and Multiple-Output

NAS Non-Access Stratumn

NB Narrow Beam

NDI New Data Indicator

NEO NEtwork Operation

NR-Node New Radio-Node

OCC Orthogonal Cover Codes

OFDM Orthogonal Frequency Division Multiplexing

PDCCH Physical Downlink Control Channel

PDSCH Physical Downlink Shared Channel

PMI Precoder Matrix Indication

PRS Positioning Reference Signals

PUSCH Physical Uplink Shared Channel

PUCCH Physical Uplink Control Channel

RAT Radio Access Technology

RB Resource Block

RE Resource Element

RI Rank Indication

RRC Radio Resource Control

RRH Remote Radio Head

RS Reference Signal

RSSI Received Signal Strength Indicator

RSRP Reference Signal Received Power

RSRQ Reference Signal Received Quality

RV Redundancy Version

SC-FDMA Single Carrier-Frequency Division Multiple Access

SI System Information

SIB System Information Block

SISO Single-Input and Single-Output

SRS Sounding Reference Signal

2D Two-Dimensional

3D Three-Dimensional

TDD Time Division Duplex

TPC Transmit Power Control

TRP Transmission and Reception Point

TTI Transmission Time Interval

TXSS Transmit Sector Sweep

UAV Unmanned Aerial Vehicle

UE User Equipment

UL UpLink

URLLC Ultra-Reliable and Low Latency Communications

VR Virtual Reality

WB Wide Beam

WRC Wireless Planning Coordination

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they have structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

What is claimed is: 1-20. (canceled)
 21. An apparatus comprising aprocessor, a memory, and communication circuitry, the apparatus beingconnected to a network via its communication circuitry, the apparatusfurther comprising computer-executable instructions stored in the memoryof the apparatus which, when executed by the processor of the apparatus,cause the apparatus to perform operations comprising: controllingtransmission of a first scheduling for a first transmission; controllingtransmission of a second scheduling for a second transmission whichpreempts one or more resources for the first transmission; sending thefirst transmission; sending the second transmission; and sending apreemption indication, through downlink control information, wherein thepreemption indication indicates that one or more resources for the firsttransmission are preempted for the second transmission.
 22. Theapparatus as recited in claim 21, wherein the preemption indication issent in a common control on downlink, wherein the common control isconfigured to be used for indicating one or more preempted resources.23. The apparatus as recited in claim 22, wherein the common control isassociated with a group common Radio Network Temporary Identifier. 24.The apparatus as recited in claim 21, wherein the first transmission isrelated to a first latency or a first priority and the secondtransmission is related to a second latency or a second priority,wherein the second latency is less than the first latency and the secondpriority is higher than the first priority.
 25. The apparatus as recitedin claim 24, wherein the first transmission is related to enhancedmobile broadband (eMBB) and the second transmission is related toultra-reliable low latency communication (URLLC).
 26. The apparatus asrecited in claim 21, wherein the preemption indication is transmitted atan allocation in time after the second transmission.
 27. The apparatusas recited in claim 26, wherein the allocation of the preemptionindication is configured in a common monitoring region, wherein thecommon monitoring region is for one or more UEs.
 28. The apparatus asrecited in claim 27, wherein the configuration of the common monitoringregion is indicated by a Radio Resource Control message.
 29. Anapparatus comprising a processor, a memory, and communication circuitry,the apparatus being connected to a network via its communicationcircuitry, the apparatus further comprising computer-executableinstructions stored in the memory of the apparatus which, when executedby the processor of the apparatus, cause the apparatus to performoperations comprising: monitoring scheduling including at least one of afirst scheduling for a first transmission; receiving the firsttransmission; monitoring a preemption indication; detecting and decodinga preemption indication, through downlink control information, whereinthe preemption indication indicates that one or more resources for thefirst transmission are preempted for a second transmission; determiningif received data is preempted based on detecting and decoding thepreemption indication.
 30. The apparatus as recited in claim 29, whereinthe preemption indication is received in a common control on downlink,wherein the common control is configured to be used for monitoring oneor more preempted resources.
 31. The apparatus as recited in claim 30,wherein the first transmission is related to a first latency or a firstpriority and the second transmission is related to a second latency or asecond priority, wherein the second latency is less than the firstlatency and the second priority is higher than the first priority. 32.The apparatus as recited in claim 31, wherein the first transmission isrelated to eMBB and the second transmission is related to URLLC.
 33. Theapparatus as recited in claim 29, wherein the preemption indication isreceived at an allocation in time after the second transmission and theallocation of the preemption indication is configured in a commonmonitoring region, wherein the common monitoring region is for one ormore UEs.
 34. The apparatus as recited in claim 33, wherein theconfiguration of the common monitoring region is indicated by a RadioResource Control message.
 35. The apparatus as recited in claim 29,wherein the apparatus is further configured to: indicate capability oflatency of the apparatus in processing received data and sending aHybrid Automatic Repeat Request (HARQ) feedback; decode the receiveddata; determine a HARQ feedback based on the decoding; and send the HARQfeedback.
 36. The apparatus as recited in claim 35, wherein the HARQfeedback comprises one or multiple bits to indicate acknowledgement(ACK) or negative acknowledgement (NACK).
 37. The apparatus as recitedin claim 36, wherein the multiple bits to indicate ACK or NACK areassociated to multiple code blocks respectively.
 38. The apparatus asrecited in claim 35, wherein the HARQ feedback is carried on a physicaluplink control channel (PUCCH), and the PUCCH is implicitly orexplicitly allocated by a downlink control information (DCI).
 39. Theapparatus as recited in claim 38, wherein the PUCCH is configured with afrequency hopping pattern.
 40. A method for wireless communication, themethod comprises: controlling transmission of a first scheduling for afirst transmission; controlling transmission of a second scheduling fora second transmission which preempts one or more resources for the firsttransmission; sending the first transmission; sending the secondtransmission; and sending a preemption indication, through downlinkcontrol information, wherein the preemption indication indicates thatone or more resources for the first transmission are preempted for thesecond transmission.